Wiadomości Chemiczne

Wiadomości Chemiczne, 2011, Vol.65

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  1. Electrooptic Kerr Effect in Chemistry
    Oleg Prezhdo, Karol Olan, Walentyna Zubkowa, Wiktor Preżdo

  2. Experimental and Theoretical Determination of the Absolute Configuration of Chiral Molecules by Chiroptical Methods
    Marcin Kwit

  3. Quest for New Immunosuppressive Drugs
    Krystyna Dzierzbicka, Grzegorz Cholewiński, Dorota Iwaszkiewicz-Grześ, Piotr Trzonkowski

  4. Biotransformations with Genetically Modified Baker's Yeast Saccharomyces Cerevisiae
    Ewa Białecka-Florjańczyk, Wanda Zamojska, Agata Kapturowska

  5. Will a Nanotube Forest Grow around Us
    ? Artur P. Terzyk, Bartosz Kruszka, Marek Wiśniewski

  6. Natural and Synthetic Lactones with Anticancer and Antimicrobial Activity
    Mazur Marcelina

  7. Okruchy. XX. Wczesne kłopoty z wiązaniem wodorowym
    Ignacy Z. Siemion

  8. Application of Mass Spectrometry Methods for Analysis of Modified Nucleotides and DNA Adducts
    Jakub Hanus, Karol Jelonek, Monika Pietrowska

  9. An Application of the Huisgen 1,3-Dipolar Cycloaddition to Modify Nukleosides and Oligonucleotides
    E. Radzikowska

  10. Biological Activity of 2,7-Naphthyridine Derivatives
    Anna Wójcicka, Edwin Wagner

  11. Nitroxyl (HNO/NO-) - the Molecule of Pharmacological Significance
    Aleksandra Augustyniak, Janusz Skolimowski, Renata Kontek, Alina Błaszczyk

  12. Biological Activity of Hydrogen Sulfide
    Joanna Malinowska, Karolina Babicz, Beata Olas

  13. Factors Influencing the Percutaneous Penetration of Active Ingerdients
    M. Jaworska, E. Sikora, J. Ogonowski,

  14. Okruchy. XXI. Ożyciu i poracach Rudolfa Hermana Günsberga
    Ignacy Z. Siemion

  15. An Anniversary of Coulometric Titration
    Jan Małyszko

  16. Application of Infrared Spectroscopy in Adsorption and Catalysis (I)
    Zenon Sarbak

  17. Application of Infrared Spectroscopy in Adsorption and Catalysis (II)
    Zenon Sarbak

  18. MOF Materials, the New Family of the Molecular Sieves with Exceptional Properties and Possible Applications
    Patryk Florczak, Ewa Janiszewska, Kamila Kędzierska, Stanisław Kowalak

  19. Complexes of d- AND f-Metal Ions with Pyridine N-Oxide and its Derivatives: Spectroscopic Studies
    Zbigniew Hnatejko

  20. Applications of Hydrolases from Animal Tissues in Organic Synthesis
    Hanna Hibner, Ryszard Ostaszewski

  21. Applications of Enzymes from Animal Tissues in Organic Synthesis, Part 2
    Hanna Hibner, Ryszard Ostaszewski

  22. Chiral Recognition by Mass Spectrometry
    Ewelina Drabik

  23. Cosmetics for Atopic Dermatitis
    Karolina Śliwa, Elżbieta Sikora, Jan Ogonowski

  24. Porphyrins Closed in Sol-Gel Matrix
    Rafał Jakub Wiglusz

  25. Felieton naukowy. Zygmunt Krasiński wobec odkryć przyrodniczych
    Ignacy Z. Siemion

  26. On the Chemical Bond Differently
    Roman F. Nalewajski

  27. Nucleophilic Substitution of Hydrogen in Nitroarenes. Analogous and Complementary Process to Electrophilic Substitution
    Mieczysław Mąkosza

  28. Chemical Markers of Unifloral Honeys
    Izabela Jasicka-Misiak, Paweł Kafarski

  29. The Alkoxide Compounds in the Synthesis of Nanomaterials
    Łukasz John, Piotr Sobota

  30. Strong Hydrogen Bonds in Selected Complexes of Organic Acids with Teramethylpyrazine
    Grażyna Bator, Lucjan Sobczyk

  31. Chemical Aspects of Targeted Anticancer Therapy I. Covalent Bond of Ligand to Carrier
    Karolina M. Werengowska, Marek Wiśniewski, Artur P. Terzyk, Natalia Gurtowska, Tomasz A. Drewa

  32. Felieton naukowy. O tym, jak się posprzeczli Dymitr Iwanowicz z Aleksandrem Michajłowiczem
    Ignacy Z. Siemion

  33. On Some Pecularities of Intermolecular and Intramolecular Interactions
    Lucjan Piela

  34. Strustural Consequences of the H-Bonding
    Tadeusz M. Krygowski, Halina Szatyłowicz

  35. The Hydrogen Bond and the other Lewis Acid-Lewis Base Interactions
    Sławomir J. Grabowski

  36. Hydroformylation in Ionic Liquids Medium
    Anna M. Trzeciak

  37. Molecular Receptors. From Receptor Molecules to Functional Materials
    Grzegorz Schroeder

  38. Adsorption Kinetics at Solid/Solution Interfaces. The Meaning of the Pseudo-First- and Pseudo-Second-Order Equations
    Wojciech Płaziński, Władysław Rudziński

  39. Oxygen, Pressure and Temperature Luminescent Sensors
    Mikhail Tsvirko, Bartosz Kalota

  40. Okruchy XXIV. Patrząc na fotografię starego rysunku
    Ignacy Z. Siemion

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ELECTROOPTIC KERR EFFECT IN CHEMISTRY

Oleg Prezhdo1, Karol Olan2, Walentyna Zubkowa2, Wiktor Preżdo2

1 Department of Chemistry, University of Rochester, Rochester, NY 14627-0216
2 Instytut Chemii, Wydział Matematyczno-Przyrodniczy, Uniwersytet Humanistyczno-Przyrodniczy Jana Kochanowskiego w Kielcach,
ul. Świętokrzyska 15 G, 25-406 Kielce


The electro-optical Kerr effect finds wide application in conformational analysis of molecules and molecular aggregates [1-5], particularly in cases where the standard X-ray and NMR techniques cannot be used. For instance, NMR allows to establish conformations of linear and cyclic unsaturated organic compounds. However, it is less effective in an analysis of molecular complexes, particularly of those that have several rotational symmetry axes. In such cases a combination of techniques based on molecular dipole moments, electro-optical Kerr effect, optical Kerr effect, IR spectroscopy, and Rayleigh scattering can be applied [6]. The foundations of conformational analysis of molecular complexes using several complementary physical approaches are developed in Ref. [7].

The electro-optical methods are particularly useful for an investigation of intramolecular interactions [8-18]. The strength, direction and other details of intramolecular interactions can be determined by analyzing the deviations of the experimental molar Kerr constant (mK) from its value calculated according to the tensor-additive scheme that operates with polarizability tensors of molecular cores and functional groups [19, 20]. For instance, using this approach it has been shown that weakening of conjugation in an electron donor-acceptor chain can lead to flattening of the molecular structure [21].

The Kerr constant is also very sensitive to intermolecular interactions [22-29]. In order to assess quantitatively an extent of the solvent effect on the mK values, both molecular and continuum models of solution structure have been used [30, 31]. The mK values are greatly affected by the mutual orientation of solvent and solute molecules, which interact by dispersive, inductive and dipole-dipole forces [32]. Hydrogen and donor-acceptor bonding have an even stronger influence on the mK values [33]. The equimolar mixtures approach developed in Ref. [34] allows to determine the molar Kerr constant (mK), dipole moment (m), equilibrium constant (K) and, ultimately, structure of a molecular complex based on measurements of the Kerr constant (B), dielectric permittivity (e), density (d) and refractive index (n) of a series of dilute solutions of the complex.

Future trends in the development of the electro-optical methods in chemistry are discussed. Theories that relate the electric-optic proprieties of molecules with their reactivity are particularly important. Such theories should be able to predict the changes in the polarizabilities and dipole moments of bonds, molecules and molecular aggregates during the course of chemical reactions.

Keywords: electro-optical Kerr effect, conformational analysis, intra-molecular interactions, intermolecular interactions, polarizability, dipole moment, Kerr constant


Wiadomości Chemiczne, 2011, 65, 1.
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EXPERIMENTAL AND THEORETICAL DETERMINATION OF THE ABSOLUTE CONFIGURATION OF CHIRAL MOLECULES BY CHIROPTICAL METHODS

Marcin Kwit

Zakład Stereochemii Organicznej, Wydział Chemii Uniwersytetu im. Adama Mickiewicza, ul. Grunwaldzka 6, 60-780 Poznań
e-mail: Marcin.Kwit@amu.edu.pl


Chirality is of paramount importance in chemistry and life sciences. Electronic circular dichroism (ECD) as well as optical rotation (OR) are fundamental properties of chiral molecules. These chiroptical properties provide rich information about conformation and configuration of the molecules. Although empirical correlations between chiroptical phenomena, mostly ECD, and molecular stereochemistry have existed for some time, the development of new accurate theoretical methods opened new opportunities for correlation of chiroptical properties with structure. Computational chemistry has made an amazing progress during the past two decades, moving this highly specialized discipline into the mainstream, and making a renaissance in chiroptical methods.

This short review is meant as an introduction to the modern approach to optical activity of chiral molecules. Some illustrative applications will put the emphasis on practical applications of the theoretical/experimental analysis of complex molecules including highly flexible bistramide C and noncovalently bonded donor-acceptor dyad. The importance of the solvent effect is briefly discussed and a typical methodology is described and its strengths and weak points are commented.

Keywords: structure, chirality, optical activity, circular dichroism, optical rotation


Wiadomości Chemiczne, 2011, 65, 33.
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QUEST FOR NEW IMMUNOSUPPRESSIVE DRUGS

Krystyna Dzierzbicka1*, Grzegorz Cholewiński1, Dorota Iwaszkiewicz-Grześ1, Piotr Trzonkowski2

1 Katedra Chemii Organicznej, Wydział Chemiczny, Politechnika Gdańska, ul. G. Narutowicza 11/12, 80-233 Gdańsk
2 Zakład Immunologii Klinicznej i Transplantologii, Gdański Uniwersytet Medyczny ul. Dębinki 7, 80-952 Gdańsk
*e-mail:kd@chem.pg.gda.pl


Transplantology is getting more and more important in medicine. Development of surgical techniques and immunosuppressive treatment enabled to establish successful transplantations with various organs and tissues. However, allografts are recognized as foreign tissues and stimulate rejection, i.e. a strong immunological response which, if not stopped, results in complete destruction of the transplanted tissue. In order to prevent the rejection patients have to be treated with immunosuppressive drugs after transplantation. Unfortunately, such a damping of immune system poses a risk of cancer or severe infections. The treatment itself is also toxic, notably when applied in a long-term maintenance therapy. Currently, adverse effects of immunosuppressive drugs are recognized as the ones to be involved significantly in chronic rejection and limitation of long survival of grafted tissues. Whereas prevention of acute rejection is mostly successful, there is still no efficient treatment for chronic graft rejection. Reduction of a dose of immunosuppressive drugs or an invention of new active substances is considered the most promising solution.

Nowadays, immunosuppressive drugs can be divided into the three main groups: agents which inhibit production of cytokines taking part in cells' activation (glicocorticosteroids, calcineurine inhibitors, mTOR inhibitors), antiproliferative compounds (azathiopirin, mycophenolate mofetil, mycophenolic acid sodium salt), and antibodies.

In this article we present new investigations towards immunosuppressive drugs, their structures and synthetic methods.

Keywords: immunosuppressive activity, immunosuppressive drugs, glicocorticosteroids, CsA, FK506, tacrolimus, MPA, MMF, MPS


Wiadomości Chemiczne, 2011, 65, 59.
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BIOTRANSFORMATIONS WITH GENETICALLY MODIFIED BAKER'S YEAST SACCHAROMYCES CEREVISIAE

Ewa Białecka-Florjańczyk, Wanda Zamojska*, Agata Kapturowska

Katedra Chemii, Wydział Nauk o Żywności, Szkoła Główna Gospodarstwa Wiejskiego ul. Nowoursynowska 166, 02-776 Warszawa
e-mail: ewa_bialecka_florjanczyk@sggw.pl *Międzywydziałowe Studium Biotechnologii, Szkoła Główna Gospodarstwa Wiejskiego ul. Nowoursynowska 159, 02-776 Warszawa


Baker's yeast Saccharomyces cerevisiae is quite commonly applied as a whole-cell biocatalysts in biotransformations - reactions based on enzymatic transformations of chemical compounds. Yeast cells are easy in cultivation and use. They are usually used to catalyze such reactions as bioreduction or hydrolysis. The full sequencing of its genome accompanied with achievements of genetic engineering allowed to design new yeast strains characterized by high conversion yield and reaction selectivity. Genetically modified cells of Saccharomyces cerevisiae catalyze biotransformations, which lead to chiral building blocks important in pharmaceutical industry (especially those obtained by reduction of α- and θ-oxoesters). "Designer yeast" is a new catalyst for Baeyer-Villiger oxidation. Recombinant yeast lipases have been discussed as useful means in biodiesel production because the microbiological method of producing of this kind of fuel has many advantages. There is a growing interest in application of modified yeast in biotransformation reactions. Modern directions to improve catalytic abilities of baker's yeast include: the use of surface display technology of enzymes, optimization or increase in availability of cofactor required for bioreduction reactions or gene knock-out, which eliminates the activity of enzymes with conflicting and unwanted stereoselectivities. Commonly used technique is also overexpression of the desired protein or expression of heterologous enzymes in yeast cells.

Keywords: Saccharomyces cerevisiae, biotransformations, whole-cell biocatalysts, genetic engineering


Wiadomości Chemiczne, 2011, 65, 93.
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WILL A NANOTUBE FOREST GROW AROUND US?

Artur P. Terzyk*, Bartosz Kruszka, Marek Wiśniewski

Wydział Chemii Uniwersytetu Mikołaja Kopernika w Toruniu,Katedra Chemii Materiałów, Adsorpcji
i Katalizy,Zespół Fizykochemii Materiałów Węglowych, ul. Gagarina 7, 87-100 Toruń
*e-mail: aterzyk@chem.uni.torun.pl


In this study we describe the methods of preparation of a new class of carbon nanotubes i.e. pure and highly organized materials: carbon nanotube forests [3, 5]. High yield of this new method is caused by an increase in catalytic activity and life of used catalysts mainly due to an addition of steam to the reaction. The assistance of steam during the synthesis (the method is called "Super Growth Chemical Vapor Deposition"[3, 5]) leads to SWNTs forests having the height up to 4.0 mm. Such result is 100 times better in terms of efficiency than the previously reported records. Such synthesized, aligned materials are extremely high, super-highly dense and vertical-standing [Figs 2-4]. Moreover, this method leads to the purest SWNT material (over 99.98%) ever made. SWNTs are very easily separable from the catalysts and could be used without further purification. Highly efficient growth of SWNTs and DWNTs forests on conducting metal foils is also discussed. It is shown that such foils made of Ni-based alloys with Cr or Fe are excellent materials for the synthesis [3, 5, Fig. 3]. Under conditions where steam is added predominantly SWNTs (having the diameter 2.8 nm) are formed. Synthesis with an addition of oxygen-containing aromatics as growth enhancers is also described [figs. 16,17]. These enhancers caused the grow of CNTs having different diameters and wall numbers under identical reaction conditions. Creation of double-walled carbon nanotubes with populations as high as 84% and with the average size of 5.4 nm is possible with an insertion of methyl-benzoate. The creation of multi-walled CNTs is possible with an addition of benzaldehyde [9, Fig. 16].

Keywords: carbon nanotube forest (SWNTs, DWNTs, MWNTs), water-assisted CVD method, "Super Growth CVD", CNT


Wiadomości Chemiczne, 2011, 65, 111.
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NATURAL AND SYNTHETIC LACTONES WITH ANTICANCER AND ANTIMICROBIAL ACTIVITY

Mazur Marcelina

Katedra Chemii, Uniwersytet Przyrodniczy we Wrocławiu, ul. Norwida 25, 50-375 Wrocław
e-mail: bakmarcelina@gmail.com


Medicine is one of the most developing branches of knowledge. But even now there are still some diseases which are impossible to cure. Different cancers, antibiotic resistant bacterial infections and fungal pathogenesis infections are still everlasting problems. Thus, two ways of solutions are proposed. First is the return to natural medicines. From the ancient times plants have been used in medicine and the natural products have been an important source of drugs. Nowadays isolation and identification of these compounds, together with the determination of their biological activity, also play an important role.

Lactones are the cyclic esters with a wide range of carbon atoms in a lactone ring. They are a very interesting group of compounds which reveal a wide spectrum of biological activity. Terpenoid, especially sesquiterpene lactones and coumarin derivatives, are found in plants of the Asteraceae and Apiaceae families as well as in many others organisms. The naturally occurring lactones often possess anti-inflamatory [1, 2], phytotoxic [3, 4], antiprotozoal [5], and antiviral activities [6]. They are also well known for their anticancer [7, 8] and antimicrobial activities [9, 10].

The second way of obtaining new biologically active lactones is the chemical synthesis of new potent structural analogs of natural bioactive compounds. However, the complexity of natural products and their derivatives may lead to limited supplies, especially when they have the chiral centers which are one of the most important factors influencing their biological activity. It also causes difficulties to determine the mechanism of action. For those reasons, structural simplification plays an important role in the development of analog design.

This review is focused on novel literature data about synthetic and natural lactones which reveal anticancer, antibacterial and antifungal activities. Presented compounds show potent biological activity and high selectivity with holding promises for further applications.

Keywords: biologically active lactones, sesquiterpene lactones, anticancer activity, antimicrobial activity


Wiadomości Chemiczne, 2011, 65, 135.
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OKRUCHY. XX. Wczesne kłopoty z wiązaniem wodorowym

Ignacy Z. Siemion

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F.Joliot-Curie 14, 50-383 Wrocław



Wiadomości Chemiczne, 2011, 65, 163.
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APPLICATION OF MASS SPECTROMETRY METHODS FOR ANALYSIS OF MODIFIED NUCLEOTIDES AND DNA ADDUCTS

Jakub Hanus, Karol Jelonek, Monika Pietrowska

Centrum Badań Translacyjnych i Biologii Molekularnej Nowotworów, Centrum Onkologii - Instytut im. Marii Skłodowskiej-Curie Oddział w Gliwicach,
ul. Wybrzeże Armii Krajowej 15, 44-101 Gliwice


Chemically modified nucleotides, which are not normally present in genetic material, are called DNA adducts. This type of DNA modifications (damage) is directly related to processes of mutagenesis and carcinogenesis. Elevated levels of DNA adducts present in genetic material reflect exposure of humans to carcinogenic factors and are markers of increased risk of cancer [1]. For this reason different methods useful for quantitative and qualitative analyses of DNA adducts are used in the field of cancer prevention and research (Tab. 1). Enzymatically-catalyzed methylation of cytosine, observed mostly in so called CpG islands, is a frequent endogenous modification of genetic material. Such a DNA methylation is a key factor involved in regulation of gene expression, and methylation status of oncogenes and tumor supressor genes is an important biomarker of carcinogenesis. As such, analytical methods for assessment of DNA methylation are of great importance for molecular diagnostics of cancer.

During the last decade significant progress has been made in methods available for quantitative, qualitative and structural analyses of biological molecules. Among intensively developed tools for bioanalyses are methods of mass spectrometry. Spectrometers that are based on two methods of ionization, namely electrospray ionization (ESI) [30] and matrix-assisted laser desorption-ionization (MALDI) [48], are particularly suitable for analyses of biological macromolecules: proteins and nucleic acids. Currently available mass spectrometers, together with microscale methods for sample preparation and separation, significantly increased sensitivity and accessible mass range of analyses. New generation of "user-friendly" instruments is developed to bring the techniques directly into the workplaces of biological and clinical investigators.

This review demonstrates representative examples of mass spectrometry techniques used for qualitative analyses of nucleotide modifications and adducts present in genetic material of humans. In this field several methods base on spectrometers with electrospray ionization. Generated ions are separated according to their mass-to-charge ratio in an analyzer by electric fields; among different ion analyzers frequently used in this methods are single or triple quadrupole and ion traps (Fig. 1). Among other methods available for assessment of DNA adducts is so called Accelerator Mass Spectrometry (Fig. 2) [41]. The most frequently applied method for the assessment of DNA methylation is based on methylation-specific PCR reaction. Products of such PCR reactions are analyzed using MALDI mass spectrometry [54] (Fig. 3). In summary, new powerful methods of mass spectrometry that made available qualitative analyses of damage and modifications of human genetic material found their important place in modern biological and medical laboratories.

Keywords: carcinogenesis, molecular diagnostics, mass spectrometry, nucleotides, DNA damage, DNA adducts, DNA methylation


Wiadomości Chemiczne, 2011, 65, 191.
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AN APPLICATION OF THE HUISGEN 1,3-DIPOLAR CYCLOADDITION TO MODIFY NUKLEOSIDES AND OLIGONUCLEOTIDES

E. Radzikowska

Centrum Badań Molekularnych i Makromolekularnych Polskiej Akademii Nauk, Zakład Chemii Bioorganicznej, ul. Sienkiewicza 112, 90-363 Łódź
e-mail: eradziko@bio.cbmm.lodz.pl


The 1,3-dipolar cycloaddition reaction between azides and terminal alkynes, known as the Huisgen reaction, constitutes a powerful tool for the synthesis of versatile molecules containing carbon - heteroatom bond. The use of a copper(I) salt in this reaction allowed Sharpless to develop the concept of "click chemistry" [1]. This strategy is based on reactions between small units characterized by mild reaction conditions, versatility, high yields and stereospecificity.

The chemistry of nucleic acids and nucleoside analogues is undergoing rapid developments and numerous compounds from these classes of compounds are used in medicinal treatment. Analogues of nucleoside constitute a class of drugs that possesses either anticancer or/and antiviral activity (against HIV, HSV, VZV or HCV viruses) [3]. Many modified oligonucleotides show biological activity. As potential drugs oligonucleotides are employed in antisense, antigen and aptamer strategies. An antisense therapeutic agent acts on the pathogenic mRNA causing inactivation of the target whereas an antigen agent acts on DNA and aptamer on unwanted protein.

It is not surprising that number of research groups are trying to join the concept of click chemistry with nucleic acids chemistry. In this way, it is possible to obtain new molecules like base- or sugar-modified nucleosides, nucleosides, bioconjugates and olignucleotides. The copper-catalyzed 1,3-dipolar cycloaddition CuAAC allows to functionalize DNA, for example by labelling it through attaching small molecules to DNA. Two general strategies have been developed for this purpose: presynthetic and postsynthetic labelling. In the presynthetic method nucleotide monomers are labelled before DNA synthesis and purification. In the postsynthetic strategy DNA containing small reactive groups is synthesized first and then it is conjugated with the desired molecules. CuAAC is also a convenient method for the synthesis of modified oligonucleotides in which phosphodiester linkage is replaced by 1,2,3-triazole or for a solid phase synthesis. Such molecules appear to be useful in medicine, molecular diagnostic (e.g. fluorescent dyes) or mechanistic molecular model in the future.

Keywords: 1,3-dipolar cycloaddition, analogues of nucleosides, "click chemistry", synthesis of modified oligonucleotide, 1,2,3-triazole, bioconjugates


Wiadomości Chemiczne, 2011, 65, 207.
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BIOLOGICAL ACTIVITY OF 2,7-NAPHTHYRIDINE DERIVATIVES

Anna Wójcicka, Edwin Wagner

Katedra i Zakład Technologii Leków,
Akademia Medyczna im. Piastów Śląskich we Wrocławiu, pl. Nankiera 1, 50-140 Wrocław
email: annaw@ktl.am.wroc.pl


2,7-Naphthyridine is one of the six structural isomers of pyridopyridines. More than one hundred years ago, Gabriel and Colman discovered the isomer 2,7-naphthyridine, and named it "copiryne" [3]. From among of all naphthyridines, the synthesis and properties of the copyrine derivatives have not yet been thoroughly investigated. This paper reviews the synthetic and natural 2,7-naphthyridine derivatives which have been reported to possess various biological activity. A large number alkaloids containing the 2,7-naphthyridine scaffold have been isolated from plants and marine organisms [13-18]. The natural marine alkaloids can be classified into two groups. The bicyclic lophocladines were isolated from the red alga Lophocladia sp. [12]. The pyridoacridines represent a large and growing class the polycyclic alkaloids from sponges, ascidians or tunicates [15, 16]. Many of this natural compounds exhibited cytotoxic, antibacterial, antiviral, antifungal and sedative activity. The broad spectrum of biological activity of copyrine alkaloids is the main of reason for the preparation of new 2,7-naphthyridine derivatives also by the synthetic route. So far, about fifty different methods of synthesizing the 2,7-naphthyridine ring have been published. This study described synthesis only biologically active 2,7-naphthyridine analogues. Biological investigations have shown that copyrine derivatives have a wide spectrum of actions. Antitumor, antimicrobial, analgesic and anticonvulsion activities have been found. Most of 2,7-naphthyridine derivatives have been studied as antitumor agents. Many papers described synthesis and pharmacological properties the best active and highly selective PDE5 inhibitor (T-0156) [55]. So far, none of 2,7-naphthyridine derivatives has been applied as a drug.

Keywords: 2,7-naphthyridine derivatives, biological activity


Wiadomości Chemiczne, 2011, 65, 235.
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NITROXYL (HNO/NO-) - THE MOLECULE OF PHARMACOLOGICAL SIGNIFICANCE

Aleksandra Augustyniak1, Janusz Skolimowski2, Renata Kontek1, Alina Błaszczyk1*

1 Katedra Genetyki Ogólnej, Biologii Molekularnej i Biotechnologii Roślin, Uniwersytet Łódzki, ul. Banacha 12/16, 90-237 Łódź
2 Katedra Chemii Organicznej, Uniwersytet Łódzki, ul. Tamka 12, 91-403 Łódź
*e-mail: ablasz@biol.uni.lodz.pl


Nitrogen compounds, as an essential component of many reactions occurring in living organisms, become the object of an extensive research. These compounds became the focus of interest after the properties of nitric oxide, currently the best known nitrogen oxide, had thoroughly been studied [1-3]. Recently, particular attention has been paid to nitroxyl (HNO/NO-), which is the product of one-electron reduction of NO [4]. Formation of nitroxyl in vivo is still controversial. It seems that this compound could be formed by the reaction of S-nitrosothiols with other thiol proteins (e.g. GSH), directly through the nitric oxide synthetase (NOS), through the oxidation of hydroxylamine by the peroxidase activity of heme proteins or as a result of reduction of nitric oxide NO [5, 6]. Nitroxyl is a liable compound due to dimerization, so it is necessary to use its donors in experiments. Angeli's salt which forms HNO at physiological pH is the most commonly used donor [7]. Moreover, Piloty's acid, cyanamide, diazonium diolates or a group of acyloxy nitroso compounds are also used. There are some difficulties with detection of nitroxyl in biological systems. So far, nitroxyl was indirectly identified by detection of N2O, a product of HNO dimerization. Presently, nitroxyl is an object of intensive studies aiming at finding techniques of its direct detection. Recently two such techniques have been designed: one using the reaction of HNO with triarylphosphines, and the other with BOT1 (staining agent) complexed with copper ions, which gives fluorescent signals revealing HNO in living cells [8, 9]. Nitroxyl turned out to have great pharmacological potential [10, 11]. It was demonstrated that this compound affected the activity of many proteins reacting with their thiol groups [12, 13]. Moreover, HNO/NO- influences the contractility of blood vessels and therefore has inotropic and lusitropic effects on myocardium [14]. Nitroxyl seems to be very promising in treating cancerous diseases as it inhibits the activity of an enzyme involved in the process which is the most important for cancer cells - glycolysis [15].

Keywords: nitroxyl, Angeli's salt, nitroxyl donors, nitric oxide


Wiadomości Chemiczne, 2011, 65, 265.
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BIOLOGICAL ACTIVITY OF HYDROGEN SULFIDE

Joanna Malinowska*, Karolina Babicz, Beata Olas

Katedra Biochemii Ogólnej, Uniwersytet Łódzki, ul. Pomorska 141/143, 90-236 Łódź, tel/fax: (0-42) 635-44-82
*e-mail: malinowskaj@hotmail.com


Hydrogen sulfide (H2S) is a well known toxic gas that is synthesized from amino acids: cysteine (Cys) and homocysteine (Hcys) by two enzymes: cystathionine-β-synthase and cystathionine-γ-lyase (Fig. 1) [3]. Hydrogen sulfide, like nitric oxide (NO) and carbon monoxide (CO) is a signaling molecule in different systems [4]. Moreover, hydrogen sulfide has other various biological properties [8]. It induces hypotension in vivo and vasodilation in vitro by opening KATP channels in vascular smooth muscle cells [2, 5, 15]. Deficiency of H2S may contribute to atherogenesis in some patients with hyperhomocysteinemia, in whom the metabolism of homocysteine to cysteine and H2S is compromised by vitamin B6 deficiency. Reduced H2S production in brain was observed in patients with Alzheimer's disease. On the other hand, excess of H2S may lead to mental homoretardation in patients with Down's syndrome and may be involved in the pathogenesis of hypotension associated with septic shock [6]. This review summarizes the endogenous metabolism, physiological and pathological function of hydrogen sulfide.

Keywords: hydrogen sulfide, homocysteine, hyperhomocysteinemia, oxidative stress, cardiovascular system


Wiadomości Chemiczne, 2011, 65, 289.
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FACTORS INFLUENCING THE PERCUTANEOUS PENETRATION OF ACTIVE INGERDIENTS

M. Jaworska, E. Sikora*, J. Ogonowski,

Instytut Chemii i Technologii Organicznej,
Wydział Inżynierii i Technologii Chemicznej, Politechnika Krakowska, ul. Warszawska 24, 31-155 Kraków
*e-mail: esikora@pk.edu.pl


This article presents main factors influencing transdermal delivery of active ingredients in cosmetic and pharmaceutical emulsions. The emulsions are widely used as vehicles, because of their excellent solubilizing properties for lipophilic and hydrophilic active ingredients.

It is shown that physicochemical properties of the active ingredients (i.e. molecular mass, polarity, lipophilicity), type of emulsion, the droplet size of dispersed phase, kind of emollients, surfactant/co-surfactant system and presence of permeation enhancer may affect the percutaneous absorption.

Keywords: percutaneous penetration, active ingredient, vehicle, emulsion, permeation enhancer


Wiadomości Chemiczne, 2011, 65, 301.
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OKRUCHY. XXI. O ŻYCIU I PRACACH RUDOLFA HERMANA GÜNSBERGA

Ignacy Z. Siemion

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F.Joliot-Curie 14, 50-383 Wrocław



Wiadomości Chemiczne, 2011, 65, 321.
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AN ANNIVERSARY OF COULOMETRIC TITRATION

Jan Małyszko

Uniwersytet Humanistyczno-Przyrodniczy Jana Kochanowskiego, Instytut Chemii, ul. Świętokrzyska 15, 25-408 Kielce
e-mail: malyszko@ujk.edu.pl


In 1938, Szebellédy and Somogyi [1-7] have proposed an important methodological innovation in analytical chemistry. This methodology was termed coulometric titration. This paper presents an overview of the principles of operation and, in broad outline, applications of this methodology. Moreover, a short biography and scientific achievements of professor Laszlo Szebellédy are presented in the introduction.

Chapter 1 of this review outlines the theoretical background and general description of coulometric titration. In this new technique, the electrical current generates a titrant that chemically reacts with an analyte. The amount of the analyte is determined from the quantity of the electrical charge passed until the point of chemical equivalence has been reached, according to the 2nd Faraday's law of electrolysis. The new methodology offers several significant advantages over a conventional volumetric procedure, such as elimination of problems connected with the preparation, standardization and storage of standard solutions.

In Chapter 2, an evolution of the method after the Second World War is presented. In these times, stable constant current sources became easy to construct [13-15]. Consequently, coulometric titrations started to use a constant current system. Under these conditions, the total number of coulombs consumed can be calculated readily from the intensity of current and the duration of electrolysis. Coulometric titrations have been developed for all types of volumetric titrations: oxidation-reduction [19-28], precipitation [17, 18], complex formation [37] and neutralization reactions [39, 40]. The generation of various titrants and possibilities of application are described. Special attention is devoted to the electrochemical generation of reagents which are not ordinarily utilized in conventional volumetric analysis owing to the instability of their solutions such as bromine, chlorine, silver(II) and titanium(III). Moreover, the coulometric titration procedure is significantly more sensitive than the volumetric titration, and it is particularly suited to automation, because complex mechanical devices such as an automatic burette are not required. The new method appeared to be an attractive alternative to all forms of the volumetric titration. Chapter 3 is dedicated to the contribution of Polish academic chemistry teachers to the development of the method discussed [57-89, 91-100].

Advantages and disadvantages of the method are listed in the last Chapter (Summary). Each Chapter includes selected works related to the history of the subject.

Keywords: coulometry, coulometric titration, conventional titrations, electrode processes, titrants


Wiadomości Chemiczne, 2011, 65, 345.
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APPLICATION OF INFRARED SPECTROSCOPY IN ADSORPTION AND CATALYSIS (I)

Zenon Sarbak

Wydział Chemii, Uniwersytet im. Adama Mickiewicza, ul. Grunwaldzka 6, Poznań
e-mail: sarbak@amu.edu.pl


The review presents some key results of infrared investigations of adsorbents and catalysts, which were obtained in Laboratory of Adsorption and Catalysis at Adam Mickiewicz University - conducted under the author guidance.

After short introduction, review is divided into seven parts. In the first chapter, there was described an application of infrared method devoted to examination of structure of different types of zeolites, such as A, X, Y and mordenite as well as alumina and fly ashes and their modifications. Moreover, some results were presented on cobalt-molybdena catalysts supported on alumina.

In the next chapter chemisorption of pyridine and t-butylnitrile (TBN) molecules on the alumina and alumina modified with fluoride and sodium ions as well as Co(Ni)-Mo(W) catalysts supported on alumina were investigated. In the last case intensity of some spectra were correlated with catalytic activity for cumene cracking. Another set of experiments were devoted to transesterification on dealuminated mordenites containing cations of alkaline earths elements and correlation with infrared results.

In the next part of review, chemisorption of ethanol was presented. It was concluded, that during chemisorption of ethanol different surface species were produced on alumina, silicaalumina and zeolites X and ZSM-5.

In separate chapter, it was considered oligomerization of different alkenes on Phillips catalyst using IR methods.

In the last chapter, ways of chemisorption of dihydrobenzenes on cobalt-molybdena catalyst were examined using IR reflectance spectra.

It seems that above presented results based on infrared examination will help to better understand adsorbents and catalysts structure and their action during adsorption and catalytic reactions.

Keywords: IR, chemisorption, adsorbents, catalysts


Wiadomości Chemiczne, 2011, 65, 363.
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APPLICATION OF INFRARED SPECTROSCOPY IN ADSORPTION AND CATALYSIS (II)

Zenon Sarbak

Wydział Chemii, Uniwersytet im. Adama Mickiewicza, ul. Grunwaldzka 6, Poznań
e-mail: sarbak@amu.edu.pl


The review presents important results on infrared examination of adsorbents and catalysts, which were obtained in Laboratory of Adsorption and Catalysis in Environmental Protection at Adam Mickiewicz University - conducted under the author guidance.

In the first chapter results on chemisorption of carbon monoxide on Pt and Pt-Sn catalysts supported on various carriers such as alumina with different specific surface area and silica were described. For these catalysts different amount of Pt or Pt and Sn were used. Besides, catalysts obtained by different preparation procedures were also investigated.

Second chapter contains description of coke deposit on alumina and silica supports as well as on Pt and Pt-Sn catalysts supported on above mentioned carriers.

Special attention was also devoted to coke deposition on aluminosilicate, zeolite type A, X and ZSM-5 and Pt-Cr, Pt-Mo and Pt-W catalysts supported on alumina.

Moreover, coke deposition on alumina contained chloride ions and molybdena(VI) ions on alumina activated by reduction and sulfidation were also investigated.

It seems that above presented results based on infrared examination will help to better understand of adsorbents and catalysts structure and their action during adsorption and catalytic reactions.

Keywords: FT-IR, carbon monoxide, chemisorption, catalyst surface, coke deposition, catalysts


Wiadomości Chemiczne, 2011, 65, 395.
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MOF MATERIALS, THE NEW FAMILY OF THE MOLECULAR SIEVES WITH EXCEPTIONAL PROPERTIES AND POSSIBLE APPLICATIONS

Patryk Florczak, Ewa Janiszewska, Kamila Kędzierska, Stanisław Kowalak

Uniwersytet im. A. Mickiewicza w Poznaniu, Wydział Chemii, ul. Grunwaldzka 6, 60-780 Poznań
e-mail: patryk84@amu.edu.pl


The metal organic frameworks (MOFs) are a novel group of molecular sieves discovered in the last decade of the twentieth century. Most of conventional molecular sieves such as microporous zeolites and zeolite-like materials, ordered mesoporous materials (M41S) are typical inorganic compounds. Although their synthesis often involves an assistance of organic compounds acting as structure directing agents and organic solvents are sometimes applied during their crystallization, the organics are always removed from resulted products (mainly by calcinations). The MOFs are crystalline materials build of metal ions or ion clusters coordinatively bonded with organic segments (linkers) that form porous (one-, two-, or three- dimensional) structures. The various coordination number of selected metal and the nature of organic linkers allow to prepare a great variety of structures with different properties. The inorganic components comprise a great variety of transition (e.g. Zn Cu, Fe, rare earths) and base metal (e.g. Al) cations of different valence. The organic linkers are functionalized compounds containing O, N, P, S atoms (i.e. carboxylates, phosphonates, sulfonates, cyanides, amines, imidazoles) enable to chelate the inorganic cations. The organic subunits can be additionally modified by substitution of other functional groups (halogens, hydroxyls, aminogroups).

The MOF materials are mostly prepared similarly as zeolitic materials by crystallization in solvothermal conditions. The solvents (water or organic compounds) can play a role of templates, although sometimes additional structure directing agents are admitted into the initial mixtures. The crystallization is always conducted in moderate temperatures (20-200°C). After removal of solvents well ordered pore systems are available for selective adsorption and for other applications. The thermal stability of this family of molecular sieves is obviously lower than that of inorganic materials, but most of them can withstand heating at 350-400°C, which still makes them suitable for variety of potential applications.

The adsorption properties of MOFs makes them very appealing for practical application. The recorded surface areas of some types are overwhelming and they surpass 5000 m2/g. The high adsorption capacity is very promising for storage of fuels (natural gas, hydrogen) or waste gases (CO2, SO2) as well as for their separation. The great and very fast growing variety of structures and chemical compositions brings also a hope to use them as efficient catalysts. The metal segments, functional groups in organic blocks as well as occluded or encapsulated species can play a role of catalytically active sites. The MOF materials can be also applied as matrices for sensors, pigments, and microelectronic or optical devices.

Keywords: organic-inorganic molecular sieves, MOF, structure, synthesis, properties, applications


Wiadomości Chemiczne, 2011, 65, 427.
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COMPLEXES OF d- AND f-METAL IONS WITH PYRIDINE N-OXIDE AND ITS DERIVATIVES: SPECTROSCOPIC STUDIES

Zbigniew Hnatejko

Wydział Chemii, Uniwersytet im. Adama Mickiewicza, ul. Grunwaldzka 6, 60-780 Poznań
e-mail: zbychuh@amu.edu.pl


This article reviews results of studies, collected in the literature, related to complexation abilities of pyridine N-oxides, including forms and properties of d- and f-metal ion complexes with this group of ligands. In this paper the synthetic pathways of the ligands, based on an oxidation of the corresponding heterocyclic compounds are presented (Scheme 3) [2, 4, 5]. Substituted pyridine N-oxides form an interesting group of compounds, which have found numerous applications [296-299, 314-318]. They have been used in catalysis, crystal engineering, synthesis of coordination polymers, as well as drugs and components in pharmaceutical chemistry [300-309]. Some of them are useful in destroying of microorganisms and the HIV virus [277, 278, 303-307]. Moreover, they are important compounds in the thermal and photochemical oxidation processes [296-299].

The complexes of metal ions with the N-oxide ligands can be formed by binding an oxygen atom of the N→O group, and/or by binding the substituents present in the aromatic ring, e.g. oxygen atoms of carboxylic groups. The complexes can be obtained in monomeric [64, 159], dimeric [58] or polymeric forms [60, 153, 175]. The formation of polymeric forms is more effective when the distance between the positions of COOH and N→O groups in the aromatic ring increases [168]. Complexes of Ln3+ ions and particularly of Eu3+ with pyridine N-oxides are good luminescent materials, better than their heterocyclic counterparts [180, 211]. The emission intensity of europium ions in these systems depends on the efficiency of the LMCT (ligand-metal charge transfer) and LMET (ligand-metal energy transfer) transitions, as well as on electron-donor properties of the substituents present in the pyridine N-oxide ring [37, 132, 155]. A special role in the complexation of Ln3+ ions plays cryptands, which can encapsulate the metal ion. This process protects the metal ion from a penetration of its first coordination sphere by solvent molecules or counterions [245, 246]. The complexes of europium(III) with macromonocyclic, macrobicyclic and acyclic ligands, equipped with photoactive units such as pyridine N-oxide, 2,2'-bipyridine-N,N'-dioxide or 3,3'-biisoquinoline-2,2'-dioxide in solutions, solid states, and incorporated in a silicate matrices by sol-gel method, gained a lot of attention [247-274].

Keywords: complexes, d- and f- metal ions, pyridine N-oxides, spectroscopy


Wiadomości Chemiczne, 2011, 65, 461.
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APPLICATIONS OF HYDROLASES FROM ANIMAL TISSUES IN ORGANIC SYNTHESIS

Hanna Hibner1, Ryszard Ostaszewski*2

1 Wydział Chemiczny Politechniki Warszawskiej ul. Noakowskiego 3, 00-664 Warszawa
2Instytut Chemii Organicznej Polskiej Akademii Nauk ul. Kasprzaka 44/52, 01-224 Warszawa
e-mail: rysza@icho.edu.pl


This work presents systematically enzymes which can be obtained form animal tissue and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolation and purification of particular enzymes. Such procedures usually are so simple that they can be used in every industrial or research laboratory.

Most animal enzymes are well-investigated and their structures and substrate specificity are known. They are used as biocatalysts in many chemical processes. Others were used in one or a few reactions but their natural substrates and biochemical properties are described. Trials of predicting potential applications of such enzymes and other substrates for them were done.

In this part typical applications of hydrolases: lipases (porcine pancreatic lipase [8-17], lamb pregastric lipase [22]), esterases (porcine, horse liver esterase, liver acetone powders [34-43, 46]), L-aminoacylase [48, 49], pepsin [56], trypsin [58, 59], imidase [52, 53], aldohexose hydrolases [60, 62-64], nucleotide pyrophosphatase [65]; were described.

Also examples of immobilized [10, 32] or recombined [49] enzymes are given in the text. These modifications enhance catalytic properties or reduce costs of using enzymes.

In practical applications a biocatalytic effect of enzymes from animal sources is often compared with microbial ones. This text is focused on processes where animal enzymes gave much better results (yield and enantioselectivity) than microorganisms. They are also proper, unlike whole microorganisms, to investigate and computer analysis of mechanism of the reaction. Enzymes isolated from animal tissues usually have well-defined structure of active site which is a key to predict mechanisms.

Keywords: animal enzymes, biocatalysis, organic synthesis, applications of hydrolases


Wiadomości Chemiczne, 2011, 65, 557.
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APPLICATIONS OF ENZYMES FROM ANIMAL TISSUES IN ORGANIC SYNTHESIS, PART 2

Hanna Hibner1, Ryszard Ostaszewski*2

1 Wydział Chemiczny Politechniki Warszawskiej, ul. Noakowskiego 3, 00-664 Warszawa
2 Instytut Chemii Organicznej Polskiej Akademii Nauk, ul. Kasprzaka 44/52, 01-224 Warszawa
e-mail: rysza@icho.edu.pl


This work shows systematically known types of animal enzymes and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolation and purification of particular enzymes. Such procedures usually are so simple that they can be used in every industrial or research laboratory.

Most animal enzymes are well-investigated and their structures and substrate specificity are known. They are used as biocatalysts in many chemical processes. Others were used in one or a few reactions but their natural substrates and biochemical properties are described. Trials of predicting potential applications of such enzymes and other substrates for them were performed.

Typical applications of:

were described.

Also examples of or recombined [24, 39, 44] enzymes are given in the text. These modifications enhance catalytic properties or reduce costs of using enzymes.

In practical applications a biocatalytic effect of enzymes from animal sources is often compared with microbial ones. This text is focused on processes where animal enzymes gave much better results (yield and enantioselectivity) than microorganisms. They are also proper, unlike whole microorganisms, to investigate and computer analysis of mechanism of the reaction. Enzymes isolated from animal tissues usually have well-defined structure of active site which is a key to predict mechanisms.

A quantitative analysis of applications of these enzymes was performed. Among animal enzymes hydrolases and oxidoreductases have found the most applications in synthesis. Transferases are also often used. Other classes of enzymes seldom act as biocatalysts. It is general tendency, true also in relation to microbial and plant enzymes.

Keywords: animal enzymes, biocatalysis, organic synthesis, applications of enzymes


Wiadomości Chemiczne, 2011, 65, 585.
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CHIRAL RECOGNITION BY MASS SPECTROMETRY

Ewelina Drabik

Centrum Badań Molekularnych i Makromolekularnych Polskiej Akademii Nauk,
Środowiskowe Laboratorium Badań Fizykochemicznych, ul. Sienkiewicza 112, 90-363 Łódź
e-mail: ewdrabik@wp.pl


The phenomenon of optical activity was discovered by Louis Pasteur in 1848. Since this time, chirality of organic compounds observed in biological systems has became a central theme in scientific research. Synthesis and quantitation of enantiomerically pure compounds is important for a wide range of applications. Chirally pure compounds are required not only by pharmacology, but they are also of interest in cosmetic and food industry and many other applications.

Similarity of enantiomers in their chemical and physical properties, except for optical rotation, makes their separation and detection very difficult. Until now, many methods have been used for the enantioselective discrimination of organic compounds, including nuclear magnetic resonance spectroscopy (NMR), circular dichroism (CD), capillary electrophoresis (CE) and chromatography (GC, HPLC), where an interference of a solvent cannot be excluded.

Recent studies have shown that mass spectrometry (MS) is an alternative approach to traditional method for chiral recognition and determination of enantiomeric composition. Although, mass spectrometry has been considered as insensitive to chirality because enantiomers have the same mass and show identical mass spectra, it is now accepted as important tool for differentiating of enantiomeric compounds through their interactions with chiral reference molecules (Fig. 1). The ability to transfer diastereomeric non-covalent complexes between chiral selectors and analyte enantiomers, which differ in stability, into the gas-phase and measure such differences trough mass spectrometric ion abundances, has appeared with development of soft ionization techniques such electrospray ionization (ESI), fast atom bombardment (FAB) and matrix-assisted laser desorption/ionization (MALDI). Mass spectrometry-based methods for chiral recognition and quantitative determination of enantiomeric purity are attractive due to their speed, high sensitivity, low sample consumption, tolerance to impurities and ability to probe the analyte in a solvent free environment.

Currently, there are four well-defined approaches for determining a measure of enantiomer discrimination, using either single-stage or tandem mass spectrometry. They can be classified into the following categories: (1) measurement of the relative abundance of diastereomeric complexes between chiral reference compound and the enantiomers (usually one isotopically labeled [10]), (2) enantioselective ion/molecule reaction between diastereomeric complexes and chiral or achiral reactants [11], (3) kinetic method [12] and (4) collision-induced dissociation (CID) of diastereomeric adducts in a tandem mass spectrometry (MS/MS) experiment [61, 62].

Over the past decade, new approaches to chiral separation and analysis of enantiomers have been introduced, where molecules are separated based on their mobility (ion mobility spectrometry) [66].

Keywords: mass spectrometry, chiral recognition, host-guest (analyte-selector) interaction, kinetic method, ion-molecule reaction, ion mobility spectrometry


Wiadomości Chemiczne, 2011, 65, 609.
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COSMETICS FOR ATOPIC DERMATITIS

Karolina Śliwa, Elżbieta Sikora, Jan Ogonowski

Instytut Chemii i Technologii Organicznej, Wydział Inżynierii i Technologii Chemicznej, Politechnika Krakowska, ul. Warszawska 24, 31-155 Kraków
e-mail: karola@chemia.pk.edu.pl


Atopic dermatitis (AD) is an inflammatory chronic, skin disorder with the multifactorial etiology. The major symptom of AD is pruritc [1]. The treatment is symptomatic and is being assisted with intensive skincare at the use of cosmetics.

In the paper generally used methods of AD therapy and the skin care were discussed. Moreover the essential ingredients of products used to the atopic skin treating were described. Some examples of cosmetic formulations were also presented.

Keywords: atopic dermatitis, cosmetics, emollients


Wiadomości Chemiczne, 2011, 65, 651.
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PORPHYRINS CLOSED IN SOL-GEL MATRIX

Rafał Jakub Wiglusz

Instytut Niskich Temperatur i Badań Strukturalnych, Polska Akademia Nauk, ul. Okólna 2, 50-422 Wrocław
e-mail: R.Wiglusz@int.pan.wroc.pl


The need for new, chemically and physically stable luminescent materials operating with UV excitations has stimulated research on luminescence properties of doped sol-gel material. In this work, it has been presented a technology of production of silica gels doped with organic molecules, lanthanide compounds and organic/inorganic composites. Optical properties of these materials as functions of temperature, concentration and excitation wavelength are presented. Dynamics of excited states has been discussed based on the decay times and emission efficiencies data. Mechanisms of ligand-to-metal energy transfer as well as other processes affecting emission efficiency are considered. Silica sol-gels doped with di-aminoacid derivatives of porphyrins: PP(Ser)2(Arg)2, PP(Ala)2 (Arg)2, PP(Met)2 (Arg)2, where Met, Arg and Ser denote methionine, serine and arginine aminoacids, respectively, and H2 TTMePP {tetrakis[4-(trimethylammonio)phenyl]-21H,23H-porphine} have been obtained and spectroscopically studied. These materials can find applications as phosphors or sensors of UV irradiation.

Keywords: porphyrins, porphyrin derivatives, lanthanide(III) ions, UV-Vis spectroscopy, luminescence; sol-gel


Wiadomości Chemiczne, 2011, 65, 675.
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FELIETON NAUKOWY. ZYGMUNT KRASIŃSKI WOBEC ODKRYĆ PRZYRODMICZYCH

Ignacy Z. Siemion

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F.Joliot-Curie 14, 50-383 Wrocław



Wiadomości Chemiczne, 2011, 65, 711.
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ON THE CHEMICAL BOND DIFFERENTLY

Roman F. Nalewajski Zakład Chemii Teoretycznej im. K. Gumińskiego, Wydział Chemii, Uniwersytet Jagielloński, ul. R. Ingardena 3, 30-060 Kraków
e-mail: nalewajs@chemia.uj.edu.pl


Alternative probes of the molecular electronic and bond structure recently derived in the Information-Theory (IT) are surveyed. The electron redistribution accompanying the bond formation, from the (molecularly placed) free atoms of the promolecule to the bonded Atoms-in-Molecules (AIM), generates the associated displacements in alternative measures of the information content of electronic probabilities. It is shown that these information densities represent sensitive probes into the entropic origins and the structure/multiplicity of chemical bonds. Local displacements in the molecular Shannon entropy and the missing information (entropy deficiency) relative to the promolecular reference provide efficient tools for detecting/localizing the chemical bonds and monitoring the promotion/hybridization changes the bonded atoms undergo in the molecular environment. The distribution of the negative non-additive Fisher information in the Atomic Orbital (AO) resolution similarly generates the "Contra-Gradience" (CG) probe for localizing the bonding regions in molecules. Illustrative applications of these novel IT tools in exploring the electronic structure and patterns of chemical bonds in typical molecules are reported.

The Orbital Communication Theory (OCT) of the chemical bond is introduced. It can be used to explore both the the overall/localized bond-orders and their covalent/ionic composition. In this description the molecule is treated as the information system which propagates the probabilities ("signals") of the underlying AO "events" of the electron allocations to basis functions. This molecular communication network generates the entropic measures of the chemical bond multiplicity and its covalent (communication noise) and ionic (information flow) components for both the molecule as a whole and its diatomic fragments. The conditional probabilities of this information scattering throughout the molecule or the subsystems of interest are generated from the superposition principle of quantum mechanics, applied in the bonding subspace of the molecule determined by the system occupied Molecular Orbitals (MO). They are proportional to the squares of the corresponding elements of the first-order density matrix, also known in the standard SCF LCAOMO MO theory as the Charge-and-Bond-Order (CBO) matrix, which are related to the quadratic (Wiberg) index of the chemical bond multiplicity. OCT uses the standard IT descriptors of the molecular information channel to characterize the scattering of electron probabilities throughout the communication network via to the system chemical bonds: the average conditional-entropy of the molecular "output" distribution given the molecular "input" signal measures the channel communication-noise due to electron delocalization and reflects the overall IT-covalency in the molecule, while the complementary descriptor of the network mutual-information (information-capacity) in the promolecular "input" and molecular "output" determines the system IT-ionicity. The diatomic bond multiplicities from OCT reproduce the Wiberg bond-order in diatomic molecules and generate efficient tools for indexing the connectivities between AIM, at the same time providing an adequate representation of the bond differentiation known from intuitive chemical considerations.

It is argued that the chemical bond concept embodies all dependencies between AO used to construct the bonding subspace of the molecule. The interaction between the specified pair of AO in the molecule thus exhibits both of the direct and indirect sources: the former results from the constructive interference between the two basis functions, while the latter have their roots in the implicit dependencies between the given basis functions through their dependence upon remaining AO in the molecular bonding subspace, due to their joint participation in the chemical bond system. Therefore, the indirect (through-bridge) contributions complement the familiar direct (through-space) bonds in the resultant pattern of the bond multiplicities in molecules. These implicit bond components, realized via AO intermediates, can be probed using both the "quadratic" bond orders of Wiberg and the associated IT descriptors of the cascade communications between AO. The explicit and implicit dependencies between basis functions in the bonding subspace can be both expressed in terms of the relevant elements of the molecular CBO matrix. The conditional probabilities of the direct and bridge (cascade) propagations of electronic probabilities between AO then determine in OCT the associated IT descriptors of these interactions. Representative results from the Hückel theory for illustrative π-electron systems (benzene, butadiene and linear polyenes) and from the standard Hartree-Fock (RHF) and Kohn-Sham (KS) calculations on butadiene, benzene and selected linear polymers are discussed. The resultant bond indices, combining the direct and indirect multiplicity contributions, are shown to generate a more balanced bonding perspective, compared to that resulting from the direct (Wiberg) bond-order approach. As illustrated for linear polymers, the direct bonding can be realized at relatively short distances, while the indirect mechanism effectively extends this range to more distant neighbors in the polymer chain.

Keywords: chemical bond, entropic bond multiplicities, localization criteria for electrons and chemical bonds, molecular communication channel, non-additive Fisher information, orbital communication theory, quadratic bond orders, indirect bonding mechanism, information theory


Wiadomości Chemiczne, 2011, 65, 729.
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NUCLEOPHILIC SUBSTITUTION OF HYDROGEN IN NITROARENES. ANALOGOUS AND COMPLEMENTARY PROCESS TO ELECTROPHILIC SUBSTITUTION

Mieczysław Mąkosza

Instytut Chemii Organicznej Polskiej Akademii Nauk, ul. Kasprzaka 44/52, 01-224 Warszawa


Nucleophiles add to electron-deficient arenes, also those containing halogens ,initially in positions occupied by hydrogen to form .H adducts. This addition is faster than addition in similarly activated positions occupied by halogens. Formation of the .H adducts is a reversible process, thus they dissociate and slower addition in positions occupied by halogens results in formation of .X adducts followed by fast departure of X. to form products of nucleophilic substitution of halogen, SNAr. In the review it is shown that there are a few ways for fast further conversion of initially formed .H adducts into products of nucleopilic substitution of hydrogen such as oxidative substitution, vicarious substitution, etc. Since formation of .H adducts is faster than .X adducts and the former undergo fast transformations into products of nucleophilic substitution of hydrogen we should accept than this is the major, primary reaction whereas conventional nucleophilic substitution of halogens, SNAr reaction ipso substitution is just a secondary process. In modern textbooks only SNAr reactions are discussed whereas nucleophilic substitution of hydrogen is not mentioned, thus it is necessary to introduce proper corrections in textbooks and teaching of this chapter of chemistry of arenes.

Keywords: nitroarenes, nucleophilic substitution, oxidation, vicarious substitution


Wiadomości Chemiczne, 2011, 65, 795.
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CHEMICAL MARKERS OF UNIFLORAL HONEYS

Izabela Jasicka-Misiak1, Paweł Kafarski1,2

1 Katedra Chemii Analitycznej i Ekologicznej Wydziału Chemii Uniwersytetu Opolskiego, ul. Kopernika, 45-040 Opole
2 Zakład Chemii Bioorganicznej, Wydział Chemiczny Politechniki Wrocławskiej, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław
e-mail: pawel.kafarski@pwr.wroc.pl


Honey is a natural food product reach in variety of chemical compounds, which are responsible for its quality and aroma. Unifloral honeys are especially attractive for buyers and are quite frequently falsified. Thus, the assessment of their quality is indispensable. Today it relays on identification of the pollen and determination of honey physicochemical properties. In this paper the new methods for the assessment of honey quality are described. They relay on analysis and identification of volatile compounds typical for certain uniflolar honeys. These compounds are called markers. These could virtually all natural products with products of decomposition of phenylalanine, terpenes, flavonoids, aromatic acids, heterocycles, caretonoids and non-typical sugars. The second approach is to study metabolome of these honeys. The most effective metabolomic studies relay on building up "finger-prints" of certain honey branch basing on relative concentrations of chosen set of volatile compounds.

Keywords: honey, food quality, breeding, natural products


THE ALKOXIDE COMPOUNDS IN THE SYNTHESIS OF NANOMATERIALS

Łukasz John, Piotr Sobota*

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F. Joliot-Curie 14, 50-383 Wrocław, Polska
e-mail: piotr.sobota@chem.uni.wroc.pl
strona internetowa: http://zn1.stud.wchuwr.pl


Polynuclear metal alkoxides are nearly as common in today's chemistry as any other simple inorganic complexes and constitute an interesting family of species with a very broad structural diversity (Fig. 3 and Tab. 1) [14]. These compounds form structural motifs which range from simple bimetallic complexes to very specific aggregates that result from the versatile coordinating abilities of an alkoxo and aryloxo ligands (Fig. 1).

For the last few decades, there has been a growing interest in the development of the chemistry of metal alkoxides. Such interest derives from their fascinating structural chemistry, interesting catalytic properties, and a high potential for industrial utilization. The fact that most of them can generate highly pure and well-defined metal oxides (Table 4) has resulted in high research activity in chemistry of materials. Alkoxides and their derivatives, e.g. organometallics, are easily accessible and consist inexpensive compounds. Moreover, alkoxide ligands are easily removable during thermal treatment in a relatively low temperatures compare to conventional methods involving inorganic salts. Such compounds already have metal-oxygen bonds established on molecular structure. Due to these, alkoxides can generate oxide ceramics in a single step - so-called single-source precursors (SSPs) [11]. SSPs deliver appropriate metal elements of a final oxide product(s) eliminating the need to match the reaction rates required from a multicomponent mixture. All of these features made the metal oxides derived from metal alkoxides highly pure products possessing specific properties, chemical and mechanical resistance, excellent functions and shapes.

The aim of this article is to serve as a guide in understanding the principles in a one step strategy for oxide ceramics using metal alkoxide compounds. It includes synthesis of alkoxides and their derivatives, the concept of SSPs strategy and design of molecular precursors for oxide ceramic materials.

Keywords: metal alkoxides, molecular compounds, oxide ceramic materials


Wiadomości Chemiczne, 2011, 65, 839.
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STRONG HYDROGEN BONDS IN SELECTED COMPLEXES OF ORGANIC ACIDS WITH TERAMETHYLPYRAZINE

Grażyna Bator, Lucjan Sobczyk

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F. Joliot-Curie 14, 50-383 Wrocław
e-mail: grazyna.bator@chem.uni.wroc.pl


In the present review our interest is focused on the hydrogen bonded complexes of tetramethylpyrazine (TMP) with strong proton donors, in particular with chloranilic (CLA) or squaric (H2SQ) acid. The x-ray diffraction studies show that, depending on the proton donor, various assemblies with the acid are formed, e.g. the infinite O-H...N hydrogen bonded chains without proton transfer in the case of the complex with CLA. On the other hand with H2SQ the assemblies of [HSQ]22--2TMP·H+ composition are created, in which the ionized HSQ-1 molecules are present in the form of dimers. These dimers are bound with the TMP·H+ cations on its both sides via the +N-H...O- hydrogen bonds. Picric acid forms with TMP the complex of the 2:1 composition with a double protonated TMP molecule. In the case of HI3 acid the interesting units of the (TMP·H+)2·TMP composition are formed, in which two TMP·H+ cations are coordinated with one TMP molecule through the +N-H...N bridges.

In the infrared spectra of the TMP complexes, both with CLA and H2SQ, the similar absorption continua are observed. They can be interpreted in terms of an asymmetric potential for the proton motion, with either the double minimum or the single broad minimum potential for the CLA and H2SQ complexes, respectively.

An analysis of the neutron scattering spectra concerns the phenomena of the tunneling splitting, quasielastic neutron scattering (QNS) and inelastic (INS) scattering. In the case of tunneling splitting neat TMP does not show any tunneling transitions in the µeV energy region, because they are overlapped by the elastic scattering band. In the case of the TMP·CLA complex four tunneling transitions are seen corresponding to the four crystallographically nonequivalent CH3 groups in the TMP molecule. In the spectrum of the complex with squaric acid the observed two transitions are ascribed to the two different CH3 groups. The two remaining CH3 group tunneling transitions are overlapped by the elastic scattering. The measurements in various low temperature ranges yield information about the shape of the CH3 group rotational potential. The shape of the potential is also reflected in the spectra of quasielastic scattering. In particular the temperature dependence of the quasielastic band allows us to find the activation energy for the CH3 rotations. Finally the inelastic neutron scattering spectra are analyzed in the energy range of the CH3 torsional modes (below 200 cm-1 = 25 meV). The analysis shows that for the complexes the torsional vibration frequencies are markedly lower than those for neat TMP. In the case of the TMP·CLA complex frequencies found are particularly low. They are close to the frequencies calculated for the TMP+ cation. A general conclusion can be drawn that in the complexes the CH3 groups behave more loosely than in neat TMP.

Keywords: tetramethylpyrazine, chloranilic acid, squaric acid, x-ray diffraction, infrared spectra, neutron scattering spectra


Wiadomości Chemiczne, 2011, 65, 869.
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CHEMICAL ASPECTS OF TARGETED ANTICANCER THERAPY I. COVALENT BOND OF LIGAND TO CARRIER

Karolina M. Werengowska1, Marek Wiśniewski1, Artur P. Terzyk1*, Natalia Gurtowska2, Tomasz A. Drewa2

1 Wydział Chemii Uniwersytetu Mikołaja Kopernika w Toruniu,Katedra Chemii Materiałów, Adsorpcji i Katalizy,
Zespół Fizykochemii Materiałów Węglowych, ul. Gagarina 7, 87-100 Toruń
2 Collegium Medicum im. Ludwika Rydygiera Uniwersytetu Mikołaja Kopernika w Bydgoszczy, Zakład Inżynierii Tkankowej
ul. M. Karłowicza 24, 85-092 Bydgoszcz
*e-mail: aterzyk@chem.uni.torun.pl


In this study we describe the most popular biomedical engineering nanoparticles including carbon nanotubes [17-20], liposomes [4-7], polymeric micells [11-13], quantum dots [3, 21-23], hydrogels [24-27], dendrimers [14-16] which are recently considered as modern drug carriers. These nanomaterials are applied for cancer diagnostic and targeted delivery of active compounds as chemotherapeutics in so called targeted therapy. Thus, we characterized the ideas of targeted therapy for which compositions of carriers with antibody are constructed (Figs. 3, 4). We also compared the traditional and targeted mechanisms [1, 3, 28-29] of drug delivery (Fig. 2). During targeted therapy only the essential dose of drug (less than during conventional chemotherapy) is delivering to the cancer cell. In additional, the application of targeted therapy reduces side effects, being very characteristic for the traditional treatment. The anticancer compound can selectively hits the target only, due to the presence of the ligands attached to the surface of nanocarirer. We characterized ligands which are often use in nanomedicine: antibodies [33-37], folic acid [30-33], peptides [33, 38, 39], aptamers [33, 40, 41] and transferrin [33, 42-44]. The purpose of this study is description of the bioconjugation of ligand-nanocarrier. This step is necessary and very important in synthesis of the novel drug delivery systems in targeted anticancer therapy. We report recent advances in the field showing the formation of amides (Figs. 6-8) [51-57], thioethers (Figs. 9-11) [52, 60-66], disulfides (Fig. 12) [69], and acethyl-hydrazone groups (Fig. 13) [73]. Special attention is paid to the process such as Diels-Alder (Figs. 14, 15) [74, 75] and "click chemistry" through the cycloaddition of Huisgen (Figs. 16, 17) [79-82]. We describe also the reaction of Staudinger [83] and the process of formation Schiff's base [84]. The processes enable very mild and selective modification of the carriers through formation of amide bound. These methods ware less popular but allow the fictionalization of nanocarriers in biomedical application. Each reaction or process needs special and individual environment and conditions, which are summarized in Table 1.

Keywords: nanocarriers of drugs, targeted therapy, ligands, covalent bond, anticancer drug delivery system


Wiadomości Chemiczne, 2011, 65, 887.
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FELIETON NAUKOWY. O TYM, JAK SIĘ POSPRZECZLI DYMITR IWANOWICZ Z ALEKSANDREM MICHAJŁOWICZEM

Ignacy Z. Siemion

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F.Joliot-Curie 14, 50-383 Wrocław



Wiadomości Chemiczne, 2010, 65, 921.
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ON SOME PECULARITIES OF INTERMOLECULAR AND INTRAMOLECULAR INTERACTIONS

Lucjan Piela

Uniwersytet Warszawski, Pracownia Chemi Kwantowej, ul. Pasteura 1, 02-093 Warszawa
e-mail: piela@chem.uw.edu.pl


The ground state electronic energy represents a complicated function of the nuclear coordinates. Even for relatively small molecules this function may have many minima in the corresponding "energy landscape", very often myriads of minima, each of them corresponding to a stable configuration of the nuclei. This is why predicting the lowest-energy conformation or configuration represents a formidable task. There were many attempts to solve this problem for protein molecules, for which it is believed their native conformation corresponds to the lowest free energy. The challenge to find this conformation from a given sequence of amino acids is known as a "second genetic code". In fact all of these attempts based on some smoothing of the energy landscape. In the article some of these smoothing techniques are described, from a generic one to those, which finally turned out to be highly successful in finding native structures of globular proteins. When discussing the contributions to the conformational energy the importance of the hydrophobic effect as well as of the electrostatic interactions has been stressed. In particular it turned out that the dipole moments of the NH and of the CO bonds in proteins functioning in nature are oriented to good accuracy along the local intramolecular electric field. Thanks to enormous effort of the protein folding community it is possible to design such amino acid sequences, which fold to the desired protein 3D structure. A certain reliable theoretical technique of protein folding has been used to study a possibility of conformational autocatalysis. It turned out that a small protein of 32 amino acids, with carefully predesigned amino acid sequence, exhibits indeed such an effect, which may be seen as a model of the prion disease propagation.


Wiadomości Chemiczne, 2011, 65, 935 .
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STRUCTURAL CONSEQUENCES OF THE H-BONDING

Tadeusz M. Krygowski1, Halina Szatyłowicz2

1 Wydział Chemii Uniwersytetu Warszawskiego, ul. Pasteura 1, 02-093 Warszawa
e-mail: tmktyg@chem.uw.edu.pl
2 Wydział Chemiczny Politechniki Warszawskiej, ul. Noakowskiego 3, 00-664 Warszawa
e-mail: halina@ch.pw.edu.pl


Hydrogen bonding belongs to the most important chemical interactions in life and geochemical processes as well as in technologies, that is documented in many review articles [1-10], monographs [11-17] and numerous publications. Figure 1 presents how "popular" are studies concerning hydrogen bonds (the term H-bond/bonding/bonded in a title, key-words or in abstract) in the last decade. First information about H-bond formation appeared at the end of XIX and a few other at beginning of XX centuries [19-24]. Most common definition of H-bonding stems from Pauling [27], whereas the newest IUPAC definition was published very recently [26].

Most frequently H-bonding is experimentally described by geometry parameters [28, 32] - results of X-ray and neutron diffraction measurements, but NMR and IR/Raman spectroscopies are also in frequent use. Characteristic of interactions by H-bonding is usually discussed in terms of energies [29-31], with use of various quantum chemical theories [54-57] and applications of various models as AIM [35, 41, 42, 45-48] and NBO [43, 44] which allowed to formulate detailed criteria for H-bond characteristics [35, 48]. H-bonds are classified as strong, mostly covalent in nature [7, 29, 34], partly covalent of medium strength [35] and weak ones, usually non-covalent [7, 29, 34, 35].

Theoretical studies of H-bonding mainly concern equilibrium systems, however simulation of H-bonded complexes with controlled and gradually changing strength of interactions [61-71] are also performed. The latter is main source of data referring to effect of H-bonding on structural properties: changes in the region of interactions, short and long-distance consequences of H-bonding.

Application of the model [61] based on approaching hydrofluoric acid to the basic center of a molecule and fluoride to the acidic one, (Schemes 2 and 3) allows to study changes in molecular structure of para-substituted derivatives of phenol and phenolate [62, 64] in function of dB...H, or other geometric parameter of H-bond strength (Fig. 2). It is also shown that CO bond lengths in these complexes is monotonically related to H-bond formation energy and deformation energy due to H-bond formation [65]. Alike studies carried out for para-substituted derivatives of aniline and its protonated and deprotonated forms [77, 78, 81] give similar picture (Fig. 3). AIM studies of anilines [77, 78] lead to an excellent dependence of logarithm of electron density in the bond critical point and geometric parameter of H-bond strength, dB...H presented in Figure 4. Substituents and H-bond formation affect dramatically geometry of amine group [66] in H-bonded complexes of aniline as shown by changes of pyramidalization of bonds in amine group (Fig. 5).

Some short- and long-distance structural consequences of H-bonding are shown by means of changes in ipso angle (for amine group) in the ring and ipso-ortho CC bond lengths (Fig. 6). Moreover, the mutual interrelations are in line with the Bent-Walsh rule [84, 86]. Changes of the strength of H-bonds in complexes of p-substituted aniline and its protonated and deprotonated derivative are dramatically reflected by aromaticity of the ring66 estimated by use of HOMA index [87, 88] (Fig. 7), where strength of H-bonding is approximated by CN bond lengths. Scheme 4 presents application of the SESE [91] (Substituent Effect Stabilization Energy) for description in an energetic scale joint substituent and H-bond formation effects.

Keywords: H-bond, substituted phenols, substituted anilines, aromaticity, AIM, NBO


Wiadomości Chemiczne, 2011, 65, 953.
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THE HYDROGEN BOND AND THE OTHER LEWIS ACID-LEWIS BASE INTERACTIONS

Sławomir J. Grabowski1,2

1 Faculty of Chemistry, University of the Basque Country UPV/EHU and Donostia International Physics Center (DIPC),
P.K. 1072, 20080 Donostia, Euskadi, Spain 2 IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Euskadi, Spain
e-mail: s.grabowski@ikerbasque.org


Hydrogen bond is analyzed very often since its importance in numerous chemical, physical and biological processes is very well known. It covers the broad range of various interactions; sometimes this is the subject of discussions and polemics if some of them may be classified as hydrogen bonds. This is because there are numerous definitions of hydrogen bond interaction, often they are hardly accepted since they are not univocal. For example one can mention different types of the proton acceptors for hydrogen bonds; one center electronegative atoms, multi-center acceptors such as π-electrons or even σ-electrons. There are the other interactions which play the key role in various processes and phenomena. All are often named as no-covalent interactions but the other term, Lewis acid-Lewis base interactions seems to be more accurate. One can mention halogen bond, hydride bond or dihydrogen bond. These interactions may be treated as counterparts or competitors of hydrogen bond. The common characteristic for them, including hydrogen bond, is the electron charge transfer from the Lewis base to the Lewis acid. It was found that the amount of this transfer corresponds roughly to the strength of the interaction.

In recent years the σ-hole concept was introduced and developed and it was applied to the Lewis base-Lewis acid interactions. According to this concept the atomic centers are characterized by the presence of the regions of positive and negative electrostatic potentials; very often both regions are detected even for atoms which are commonly known as electronegative ones. In such a way halogen atoms, especially if connected by covalent bond with carbon, may act as Lewis acids and also as Lewis bases. In the first case the halogen bond is formed, recently extensively studied.

In this review the characteristics of different Lewis base-Lewis acid interactions are given as well as their common features are presented.

Keywords: hydrogen bond, halogen bond, hydride bond, Lewis acid-Lewis base interaction, The 'Atoms in Molecules' theory


Wiadomości Chemiczne, 2011, 65, 975.
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HYDROFORMYLATION IN IONIC LIQUIDS MEDIUM

Anna M. Trzeciak

Uniwersytet Wrocławski, Wydział Chemii, ul. F. Joliot-Curie 14, 50-383 Wrocław
e-mail: anna.trzeciak@chem.uni.wroc.pl


The hydroformylation reaction was discovered by Otto Roelen in 1938. He studied the side processes occurring during the Fischer-Tropsch synthesis with a cobalt catalyst and found some amounts of aldehydes formed from the olefin and syngas (H2CO) [1].

The hydroformylation found application in the chemical industry, mainly for production of n-butanal from propene. Aldehydes obtained by propene hydroformylation are subsequently hydrogenated to alcohols, used as solvents. Butanal can also be condensed to C8 aldehydes and alcohols, 2-ethylhex-2-enal and 2-ethylhexanol, important components for plasticizers such as dioctylphtalate. The hydroformylation reaction can be applied not only for the synthesis of aldehydes but also for other products. In particular, successful synthesis of quaternary carbon centers by hydroformylation has been reported in which the rhodium catalyst was modified with a ligand that serves as a catalytic directing group by covalently and reversibly binding to both the substrate and the catalyst.

Ionic liquids have been recognized as a novel class of solvents which can be successfully used for homogeneous catalysis [4]. Application of ionic liquids, non-aqueous and non-volatile solvents, has made it possible to construct biphasic systems in order to efficiently separate catalysts from organic products. It is also important that the properties of ionic liquids, such as solubility, acidity, or coordination ability, can be tuned by the use of different cations and anions.

In the ideal case, the ionic liquid is able to dissolve the catalyst and displays partial miscibility with the substrate. If the products have negligible miscibility in the ionic liquid, they can be removed by simple decantation, without extracting the catalyst. If the products are partially or totally miscible in the ionic liquid, separation of the products is more complicated [4e, 4h].

The main problem with catalytic systems for hydroformylation containing ionic liquid phase was a significant leaching of the catalyst out of the ionic liquid phase, which can be overcome by modifying neutral phosphane with ionic groups. Examples of such systems are presented in the article.

It was revealed that N-heterocyclic carbenes were formed in the biphasic hydroformylation reactions promoted by Rh complexes in an imidazolium ionic liquid [10]. Consequently, reactivity of the in situ formed Rh-carbene complexes can strongly influence on the hydroformylation reaction course [11].

The best methodology to perform the hydroformylation reaction would be a flow system in which the catalyst remains in the reactor and the substrates and products flow continuously into and out of the reactor. For the construction of such a system with soluble rhodium catalysts, ionic liquids could be considered as media used for the immobilization of the catalyst. The first example of continuous flow hydroformylation was reported by Cole-Hamilton [19, 20]. Different Supported Ionic Liquid Phase (SILP) catalysts have been examined in hydroformylation [15-17]. Interestingly, the neutral ligand can be applied efficiently in a continuous gas-phase SILP process, while in a typical biphasic system containing ionic liquid and organic solvent it would leach into the product phase.

Keywords: catalysis, hydroformylation, ionic liquids; rhodium, N-heterocyclic carbene


Wiadomości Chemiczne, 2011, 65, 1003.
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MOLECULAR RECEPTORS. FROM RECEPTOR MOLECULES TO FUNCTIONAL MATERIALS

Grzegorz Schroeder

Uniwersytet im. A. Mickiewicza, Wydział Chemii, ul. Grunwaldzka 6, 60-780 Poznań
e-mail: schroede@amu.edu.pl


The getting knowledge of the methods of chemical compounds synthesis on the planned construction site, both in terms of arrangement of atoms and functional groups, as well as spatial structure, allowed to obtain a number of new molecular receptor systems that are capable to creating host-guest complexes. The paper will present the way of the proceedings from molecular receptor to new material with this receptor, so in other words from individual molecules to the new material with specific and previously planned properties. This process is presented for two types of molecules: aryloboronic acids and terpyridine.

The ability for rapid and reversible formation of boronic acids, esters of 1,2- and 1,3-diols resulted in that these compounds were used for the synthesis of sugar receptors and consequently to build the new generation of the sensors of sugars.

2,2':6,2'-Terpyridine is ligand, that in solution forms complexes with most transition metal ions. This compound is used for the synthesis of functional polymers, dendrymers and fluorescent sensors of ions.

The presentation of the applicability of molecular receptors in the preparation of new functional materials promotes the new approach to the work of chemists. The basic research in which we define the properties of individual molecules and molecular receptors can be the beginning of the application of these compounds in the material chemistry. Additionally it can lead to the synthesis of the new materials with the specific properties or the selective construction of the measuring systems.

The process from the molecule that is characterized by well-studied properties to modern material chemistry is limited only by the imagination of chemists and by the demand for new organic materials in the industry and by the new generation of the selective measurement systems.

Keywords: molecular receptor, functionalized materials, material chemistry, boronic acids, terpyridine


Wiadomości Chemiczne, 2011, 65, 1021.
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ADSORPTION KINETICS AT SOLID/SOLUTION INTERFACES. THE MEANING OF THE PSEUDO-FIRST- AND PSEUDO-SECOND-ORDER EQUATIONS

Wojciech Płaziński1 , Władysław Rudziński1,2

1 Instytut Katalizy i Fizykochemii Powierzchni im. J. Habera, Polska Akademia Nauk, ul. Niezapominajek 8, 30-239 Kraków
2 Zakład Chemii Teoretycznej, Wydział Chemii Uniwersytetu Marii Curie-Skłodowskiej, pl. M. Curie-Skłodowskiej 3, 20-031 Lublin
e-mail: wojtek_plazinski@o2.pl


Niniejsza praca poświęcona jest omówieniu równań pseudo-pierwszorzędowego (ang. pseudo-first order, PFO) oraz pseudo-drugorzędowego (ang. pseudo-second order, PSO), ich podstawom teoretycznym oraz przyczynach stosowalności. Wyrażenia te są powszechnie wykorzystywane w próbach opisu teoretycznego procesu kinetyki adsorpcji na granicy faz roztwór/ciało stałe. Wykazano, że mogą one odpowiadać (w przybliżeniu) wielu różnym modelom fizycznym. Pociąga to za sobą konkluzję, że z faktu dobrej/złej korelacji eksperymentalnych kinetycznych izoterm adsorpcji przez równanie PSO lub PFO nie wynikają żadne wnioski odnośnie mechanizmu rządzącego szybkością adsorpcji w danym układzie.

Keywords: adsorpcja, sorpcja, modele kinetyczne, równanie Lagergrena


Wiadomości Chemiczne, 2011, 65, 1055.
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OXYGEN, PRESSURE AND TEMPERATURE LUMINESCENT SENSORS

Mikhail Tsvirko, Bartosz Kalota

Akademia im. Jana Długosza, Instytut Chemii, Ochrony Środowiska i Biotechnologii, al. Armii Krajowej 13/15, 42-200, Częstochowa
e-mail: m.tsvirko@ajd.czest.pl


Optical chemical sensors enlarge the definition of a classical chemical sensor; they present results in two-dimensional (2D) or three-dimensional (3D) aspect. They can determine parameters of micro and macro scale objects without using a lot of electronic equipment.

This article is focused on sensors based on porphyrin derivatives and europium complexes, being the most frequently used substances sensitive to oxygen concentration, pressure and temperature changes. Along with the presentation of characteristics of substances employed to sensors' construction, also the general principle of luminescent sensors operation, composition and operation range of selected mono- and bifunctional luminescent sensors are described; moreover the selected achievements, such as the "traffic light" sensor are shown.

Keywords: luminescence, metalloporphyrins, europium complexes, oxygen sensors, pressure sensors, temperature sensors


Wiadomości Chemiczne, 2011, 65, 1069.
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OKRUCHY XXIV. PATRZĄC NA FOTOGRAFIĘ STAREGO RYSUNKU

Ignacy Z. Siemion

Wydział Chemii Uniwersytetu Wrocławskiego, ul. F.Joliot-Curie 14, 50-383 Wrocław



Wiadomości Chemiczne, 2011, 65, ??.
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