Wiadomości Chemiczne

Wiadomości Chemiczne, 1996, 50.

Back   |  Home page

  1. Protein dynamics and microscopic theory of enzymatic reactions
    Michał Kurzyński

  2. Perspectives in using liquid crystals to stabilize functional conformation of proteins
    Leszek Konieczny, Barbara Piekarska, Irena Roterman, Janina Rybarska, Marek Skowronek, Barbara Stopa

  3. How water contributes to the phospholipid membrane stability as studied by a molekular dynamics simulation
    Marta Pasenkiewicz-Gierula

  4. Design of low-molecular, mechanism-based ihibitors of proteolytic enzymes
    Paweł Kafarski, Roman Gancarz

  5. Thrombin inhibitors
    Zbigniew Szewczuk

  6. Average distance and distance distribution estimation by steady-state energy transfer measurements
    Wiesław Wiczk, Leszek Łankiewicz

  7. Nuclear magnetic resonance studies on structure of actin
    Genowefa Ślósarek

  8. Coordination ability of sulfonamide bond in complexes of copper(II) ions
    Teresa Kowalik-Jankowska

  9. Notatki biograficzne. Stefan Kopeć (1888-1941)
    Karel Slama, Danuta Konopińska

  10. Notatki chaotyczne. VI. O chemii archeologicznej i archeologii molekularnej
    Ignacy Z. Siemion

  11. The metal-templated synthesis of the macrocycklic Schiff bases
    Wanda Radecka-Paryzek, Violetta Patroniak-Krzyminiewska

  12. Lipases in organic synthesis
    Ewa Haliniarz, Barbara Lejczak

  13. Synthesis of pyrans by heterodiene cykloaddition
    Krystyna Bogdanowicz-Szwed, Aleksandra Pałasz

  14. Polymers with azide groups as a component of high energetic materials
    Michał Syczewski

  15. Synthesis of organic peroxy compounds
    Stefan Baj, Małgorzata Dawid

  16. Methods to obtain propylene oxide
    Andrzej Ledwig

  17. Environmental pollution and cancer: some misconceptions
    Bruce N. Ames, Lois Swirsky Gold

  18. Notatki chaotyczne. VII. O układaniu pasjansów chemicznych
    Ignacy Z. Siemion

  19. Nitrogen bases showing strong proton-acceptor properties
    Grzegorz Schroeder, Bogusława Łęska

  20. Properties and applications of tetraazamacrocyclic complexes of transition metals
    Grzegorz Rosłonek, Joanna Taraszewska

  21. Methanol fuel cells
    Jan Przyłuski, Zbigniew Połtarzewski

  22. Transition metal nitrides and carbides - new type of hydrotreatment catalysts
    Janusz Trawczyński, Jerzy Walendziewski

  23. Dioxine: perceptions, estimates, measures
    Michael Gough

  24. Glassy metals in elektrochemistry. Passivity and electrocatalytic properties
    Maria Janik-Czachor, Anna Wołowik

  25. Uczony czy naukowiec, czyli o przeświadczeniach w nauce
    Przemysław Mastalerz

  26. Notatki chaotyczne. VIII. O analogii w chemii
    Ignacy Z. Siemion

  27. The beginings of physical chemistry at Lvov University - Bronisław Lachowicz as a physical chemist
    Zdzisław Ruziewicz

  28. Molecular modelling methods. Part I: Basic techniques and challenging problems
    Bogdan Lesyng, J. Andrew McCammon

  29. Molecular modeling methods. Part II: Present state and perspectives
    Bogdan Lesyng

  30. Application of total relaxation field of 1-H noe and molecular modeling to stereochemical studies of organic compounds
    Lech Kozerski, Robert Kawęcki, Piotr Krajewski

  31. Kinetics of fast bimolecular reactions studied by fluorescence quenching.
    Part I: Theory of the transient effect

    Marek Sikorski

  32. Application of the Hammett equation to proton transfer reactions for polyfunctional and tautomeric compounds
    Ewa Daniela Raczyńska

  33. Notatki chaotyczne. IX. Intuicje i iluminacje
    Ignacy Z. Siemion

  34. Women in science
    In the scientific circle of Maria Skłodowska-Curie

    Maria Cieślak-Golonka

  35. Crystal structure refinement from powder data - the Rietveld method
    Joanna Lutosławska-Rogóż, Stanisław A. Hodorowicz

  36. Differences in chemical behaviour of isotopes as exemplified by 238U and 235U
    Tomasz Mioduski

  37. Anion receptors
    Wojciech Wróblewski, Zbigniew Brzózka

  38. War gases in Southern Baltic Sea
    Krzysztof Korzeniewski

  39. Analysis of structural and energetic properties of microporous carbonaceous adsorbents
    Jerzy Choma, Mieczysław Jaroniec

  40. Catalytic conversion of methane to ethylene by oxidative coupling
    Andrzej Machocki

  41. Notatki chaotyczne. X. O błędach. Niebezpieczeństwa ekstrapolacji.
    Ignacy Z. Siemion

  42. Applications of neural self-organizing maps in chemistry
    Jarosław Polański

  43. The linear model of the chemical equation
    Piotr Kosztołowicz

  44. Kinetics of fast bimolecular reactions studied by fluorescence quenching. Part II: Transient effect - comparison of theory with experiment
    Marek Sikorski

  45. Beneficial radiation
    Zbigniew Jaworowski

  46. Zirconium dioxide in catalysis. Properties and application
    Andrzej Lewicki, Tadeusz Paryjczak, Jacek Rynkowski

  47. Bromine-containing oxidation by-products in water treatment
    Jacek Nawrocki, Sławoir Biłozor

  48. Solid state NMR studies of the structure and dynamics of the phosphoroorganic dichalcogenides
    Marek J. Potrzebowski

  49. Notatki chaotyczne. XI. O błędach. Błędy sztuki
    Ignacy Z. Siemion

Back   |  Home page


PROTEIN DYNAMICS AND MICROSCOPIC THEORY OF ENZYMATIC REACTIONS

Michał Kurzyński

Instytut Fizyki, Uniwersytet im. A. Mickiewicza, ul. Matejki 48, 60-769 Poznań, e-mail: kurzphys@phys.amu.edu.pl


Formulation of an advanced statistical theory of biochemical processes needs simple but adequate models of phenomena underlying microscopic dynamics of biomolecules, in particular enzymatic proteins. A synthetic picture of protein dynamics emerging from the recent studies is outlined and two classes of theoretical models of slow activated dynamics of conformational transitions within the native state are described. In models of the Protein-Glass type, successive conformational transitions are treated as diffusion of structural defects in liquid-like regions surrounding solid-like fragments of protein secondary structure. Alternatively, in models of the Protein-Machine type, the dynamics of conformational transitions is approximated by a quasi-continuous diffusive motion of solid-like structural elements relative to each other. A particular Protein-Machine model is applied in constructing a microscopic theory of enzymatic reaction involving a single chemical transformation of substrate. The rule seems to be that it is the process of conformational diffusion, and not the details of chemical transformation, that affects the rate of enzymatic reactions. Under this assumption the reaction pathways in the initial and stationary stages can differ. A possibility is indicated of direct coupling of several reactions taking place at the same multienzyme complex.


Wiadomości Chemiczne, 1996, 50, 3.
Back   |  Home page


PERSPECTIVES IN USING LIQUID CRYSTALS TO STABILIZE FUNCTIONAL CONFORMATION OF PROTEINS

Leszek Konieczny1, Barbara Piekarska1, Irena Roterman2, Janina Rybarska1, Marek Skowronek1, Barbara Stopa1

1Instytut Biochemii Lekarskiej Collegium Medicum, Uniwersytet Jagielloński, ul. Kopernika 7, 31-034 Kraków
2Zakład Biostatyki i Informatyki Medycznej Collegium Medicum, Uniwersytet Jagielloński, ul. Kopernika 17, 31-501 Kraków


The close-packed structure of a protein molecule stabilized by a cooperative network of interactions forms a unit in which local alterations induced by binding of ligands may be propagated to other parts. The disruption of tertiary interaction, which associates the larger alterations, introduces local melting of protein structure. Chromonic liquid crystalline meso-phase entities of rod-like or ribbon-like supra-molecular organisation recognise and anchor to molten areas in b-pleated sheets, stabilising the altered conformation. This again produces higher stability for the ligand-protein complex and hence may be followed by increased activity or inhibition, opening the prospect for practical use of this phenomenon.


Wiadomości Chemiczne, 1996, 50, 29.
Back   |  Home page


HOW WATER CONTRIBUTES TO THE PHOSPHOLIPID MEMBRANE STABILITY AS STUDIED BY A MOLECULAR DYNAMICS SIMULATION

Marta Pasenkiewicz-Gierula

Zakład Biofizyki, Instytut Biologii Molekularnej, Uniwersytet Jagielloński, al. Mickiewicza 3, 31-120 Kraków


Construction and thermalization of a hydrated phosphatidylcholine bilayer is described. In the liquid-crystalline phase of the bilayer, which corresponds to the physiological state of biomembranes, a large number of phospholipid molecules are linked by water molecules to form clusters. These water bridges decay and form continually but the lifetime of a fraction of them is in the nanosecond time scale. These suggest a possibility that water bridges can, together with other interactions, stabilize the membrane structure.


Wiadomości Chemiczne, 1997, 50, 41.
Back   |  Home page


DESIGN OF LOW-MOLECULAR, MECHANISM-BASED INHIBITORS OF PROTEOLYTIC ENZYMES

Paweł Kafarski, Roman Gancarz

Instytut Chemii Organicznej, Biochemii i Biotechnologii Politechniki Wrocławskiej, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław


The design and development of new drugs for existing diseases is increasingly concerned with enzyme inhibitors. Very considerable progress has been made in this area over the last few years, especially with the advent of mechanism-based inactivators, heralded by the use of low-molecular inhibitors of proteolytic enzymes. Basing on the chemical mechanism of enzymatic catalysis these enzymes were divided into four groups: serine, cysteine, aspartic and metallo-proteinases. The knowledge of catalytic function at their active sites is a good basis for the design of potent inhibitors of these enzymes as shown in this paper using representative examples.


Wiadomości Chemiczne, 1997, 50, 51.
Back   |  Home page


THROMBIN INHIBITORS

Zbigniew Szewczuk

Instytut Chemii, Uniwersytet Wrocławski, ul. F.Joliot-Curie 14, 50-383 Wrocław


Thrombin plays an important role in thrombosis and hemostasis. On the other hand, thrombin may also be involved in pathological situations such as thromboembolic disorders. Thus, it is important to be able to control the action of this enzyme. A great number of synthetic direct thrombin inhibitors have recently been made. They block either the thrombin catalytic site and/or an anion-binding exo-site which is a recognition site for some of its substrates (fibrinogen, thrombin receptor, thrombomodulin) or act on the enzyme both sites (bivalent inhibitors). This review article describes the design based on the crystal structure and structure-activity relationships, of new potent, bivalent thrombin inhibitors.


Wiadomości Chemiczne, 1997, 50, 77.
Back   |  Home page


AVERAGE DISTANCE AND DISTANCE DISTRIBUTION ESTIMATION BY STEADY-STATE ENERGY TRANSFER MEASUREMENTS

Wiesław Wiczk, Leszek Łankiewicz

Wydział Chemii, Uniwersytet Gdański, ul. Sobieskiego 18, 80-952 Gdańsk


Radiationless energy transfer is a widely used method in studies on structure and dynamics of conformational changes of biomolecules. Steady-state measurements of energy transfer are applied to estimate an average interchromophoric distance and also to study distance distribution using dynamic fluorescence quenching or performing measurements for series of compounds with different critical Förster distances but having the same conformation. In this review theoretical and practical aspects of fluorescence energy transfer are described.


Wiadomości Chemiczne, 1996, 50, 99.
Back   |  Home page


NUCLEAR MAGNETIC RESONANCE STUDIES ON STRUCTURE OF ACTIN

Genowefa Ślósarek

Zakład Biofizyki Molekularnej, Instytut Fizyki, Uniwersytet im. A.Mickiewicza, ul. Umultowska 85, 61-614 Poznań


Actin is probably the most abundant protein in nature, present in all eucariotic cells, always involved in determination of the shape and mobility of the cell. This review presents NMR data which concern the effect of the actin polymerization, a structure of its nucleotide complex and the effect of Ca2+/Mg2+ metal ion exchange at the high-affinity binding site.


Wiadomości Chemiczne, 1996, 50, 125.
Back   |  Home page


COORDINATION ABILITY OF SULFONAMIDE BOND IN COMPLEXES OF COPPER(II) IONS

Teresa Kowalik-Jankowska

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


This article is a short review considering the metal ions interaction, mostly Cu2+ ions, with sulfonamide moiety. Different coordination behaviour of ligands containing this donor system depends on metal ion and the conditions in which complexes are formed. Sulfonoamide substituent on the N-terminal amino group of amino acids and peptides is very effective binding site to Cu(II) ion due to more acidic nitrogen of sulfonamide group. The para-substituent of phenylsulfonyl moiety have very strong impact on sulfonamide nitrogen binding ability.


Wiadomości Chemiczne, 1996, 50, 143.
Back   |  Home page


Notatki biograficzne. STEFAN KOPEĆ (1888-1941)

Karel Slama1, Danuta Konopińska2

1Institute of Entomology Czech Academy of Sciences, ul. Branisowska 31, Ceske Budejovice, Czech Republik
2Wydział Chemii Uniwersytetu Wrocławskiego, ul F.Joliot-Curie 14, 50-383 Wrocław


The subject of the paper is the scientific biography of Polish biologist - Stefan Kopeć, who as the first discovered endocrinology system of insects.


Wiadomości Chemiczne, 1996, 50, 155.
Back   |  Home page


Notatki chaotyczne. VI. O CHEMII ARCHEOLOGICZNEJ I ARCHEOLOGII MOLEKULARNEJ.

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1996, 50, 161.
Back   |  Home page


THE METAL-TEMPLATED SYNTHESIS OF THE MACROCYCLIC SCHIFF BASES

Wanda Radecka-Paryzek, Violetta Patroniak-Krzyminiewska

Wydział Chemii, Uniwersytet im. A. Mickiewicza, ul. Grunwaldzka 6, 60-780 Poznań


Recognition of the importance of complexes containing macrocyclic ligands for bioinorganic chemistry, supramolecular catalysis, biomedical applications, for separation and encapsulation processes, formation of compounds with unusual properties and structures, has led to a considerable efforts in developing reliable syntheses for these compounds. The effective method for the synthesis of macrocyclic Schiff base complexes involves an in situ approach wherein the presence of a metal ion in the cyclization reaction markedly increases the yield of the cyclic product. The metal ion plays an important role in directing the steric course of the reaction and this effect has been termed the metal-template effect. This article reviews the progress made in synthesis of metal ion complexes of Schiff base macrocycles through application of the above technique. The factors which prove to be of importance in directing the synthetic pathway in the Schiff base systems and must be taken into account in the design and synthesis of the desired products, are discussed.


Wiadomości Chemiczne, 1996, 50, 171.
Back   |  Home page


LIPASES IN ORGANIC SYNTHESIS

Ewa Haliniarz, Barbara Lejczak

Instytut Chemii Organicznej, Biochemii i Biotechnologii Politechniki Wrocławskiej, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław


Among numerous enzymes useful for organic synthesis, lipases are the most widely used. These enzymes have several properties which make them interesting as catalysts in organic synthesis, for instance, wide substrate acceptability, ease of handling, non-requirement for co-factors and, moreover, they are catalytically active in organic solvents. This paper reviews useful reactions catalyzed by lipases. Special attention is focused on the synthesis of biologically active compounds.


Wiadomości Chemiczne, 1996, 50, 193.
Back   |  Home page


SYNTHESIS OF PYRANS BY HETERODIENE CYCLOADDITION

Krystyna Bogdanowicz-Szwed, Aleksandra Pałasz

Wydział Chemii Uniwersytetu Jagiellońskiego, ul. Ingardena 3, 30-060 Kraków


Two approaches to synthesis of pyran derivatives by heterodiene cycloaddition are reviewed. The first is the cycloaddition with the inverse electron demand of 1-oxa-1,3-butadiene with enol ethers or enamines. The second is the cycloaddition of 1,3-butadienes to carbonyl compounds. Some examples of the application of this methodology in synthesis of natural products are presented.


Wiadomości Chemiczne, 1996, 50, 213.
Back   |  Home page


POLYMERS WITH AZIDE GROUPS AS A COMPONENT OF HIGH ENERGETIC MATERIALS

Michał Syczewski

Zakład Materiałów Wysokoenergetycznych, Wydział Chemiczny, Politechnika Warszawska, ul. Noakowskiego 3, 00-664 Warszawa


In spite of the general opinion about the azide group, polymers containing them are sufficiently safe and stable materials. This fact has been explained on the basis of the special and general properties of the azide groups.

In this paper we present the following subjects connected with these polymers: methods of monomers and oligomers preparation, oligomers crosslinking and curing. Particular attention is paid to thermochemical properties of the azide polymers and high energetic materials composed of them.


Wiadomości Chemiczne, 1996, 50, 241.
Back   |  Home page


SYNTHESIS OF ORGANIC PEROXY COMPOUNDS

Stefan Baj, Małgorzata Dawid

Instytut Chemii i Technologii Organicznej, Politechnika Śląska, ul. B. Krzywoustego 4, 44-101 Gliwice


The variety of synthesis methods of organic peroxides R1OOR2 (R1 = H, alkyl, aralkyl; R2 = alkyl, aralkyl) have been reviewed.


Wiadomości Chemiczne, 1996, 50, 261.
Back   |  Home page


METHODS TO OBTAIN PROPYLENE OXIDE

Andrzej Ledwig

Instytut Ciężkiej Syntezy Organicznej "Blachownia", ul. Energetyków 9, 47-225 Kędzierzyn-Koźle


Methods to obtain propylene oxide, both the commercial ones and those under investigation, are reviewed.


Wiadomości Chemiczne, 1996, 50, 295.
Back   |  Home page


ENVIRONMENTAL POLLUTION AND CANCER: SOME MISCONCEPTIONS

Bruce N. Ames, Lois Swirsky Gold

Translation from book Phantom Risk: Scientific Inference and the Law, MIT Press 1993


The public has many misconceptions about the relationship between environmental pollution and human cancer. Underlying these misconceptions is an erroneous believe that nature is benign. Below we highlight eight of these misconceptions and describe the scientific information that undermines each one.


Wiadomości Chemiczne, 1996, 50, 317.
Back   |  Home page


Notatki chaotyczne. VII. O układaniu pasjansów chemicznych.

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1996, 50, 345.
Back   |  Home page


NITROGEN BASES SHOWING STRONG PROTON-ACCEPTOR PROPERTIES

Grzegorz Schroeder, Bogusława Łęska

Wydział Chemii Uniwersytetu im. A. Mickiewicza, ul. Grunwaldzka 6, 60-780 Poznań


In this paper we report the proton-acceptor properties for very strong neutral nitrogen bases as: guanidines, amidines, proton sponges, poliamines, cryptands and Schwesinger bases (phosphazenes).


Wiadomości Chemiczne, 1996, 50, 367
Back   |  Home page


PROPERTIES AND APPLICATIONS OF TETRAAZAMACROCYCLIC COMPLEXES OF TRANSITION METALS

Grzegorz Rosłonek, Joanna Taraszewska

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


In this review are presented the physico-chemical and electrochemical properties of tetraazamacrocyclic complexes of transition metals, especially of Ni, and applications of this class of complexes in catalysis, analysis and medicine.


Wiadomości Chemiczne, 1996, 50, 399.
Back   |  Home page


METHANOL FUEL CELLS

Jan Przyłuski, Zbigniew Połtarzewski

Zakład Technologii Ciała Stałego, Wydział Chemiczny, Politechnika Warszawska, ul. Noakowskiego 3, 00-664 Warszawa


Fuel cell is a system which converts chemical energy of a fuel and an oxidant directly into the electrical energy. Methanol fuel cell seems to be promising for large-scale commercialization, in contrast to hydrogen-fed cells, especially in transportation. The limitation for methanol system is nowadays due to low catalytic activity of the electrodes, especially anodes. The best catalytic material seems to be platinum in composition with some other metals, as tin and ruthenium, which act as promotors of electrochemical processes. Promotors weaken the negative influence of catalyst poisons generated during the oxidation of methanol. Application of solid polymer electrolytes in methanol fuel cell allows to elevate the working temperature of the cell, which results in higher current densities. Methanol fuel cell presents several advantages: lack of toxic emission (CO, hydrocarbons, lead, sulphur), relatively low operating temperature.


Wiadomości Chemiczne, 1996, 50, 437.
Back   |  Home page


TRANSITION METAL NITRIDES AND CARBIDES
- NEW TYPE OF HYDROTREATMENT CATALYSTS

Janusz Trawczyński, Jerzy Walendziewski

Instytut Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej, ul. Gdańska 7/9, 50-344 Wrocław


Interstitial alloys are formed by the incorporation of nitrogen or carbon into the lattices of early transition metals to produce a class of compounds with metallic character. They demonstrate excellent catalytic activity, similar to those of noble metals in wide variety of reactions: hydrogenolysis, hydroprocessing, isomerization, ammonia synthesis. Methods of synthesis as well as the structure of interstitial alloys are reviewed. Results of investigation of their catalytic properties as the hydrotreatment catalysts are reviewed and discussed.


Wiadomości Chemiczne, 1996, 50, 455.
Back   |  Home page


DIOXINE: PERCEPTIONS, ESTIMATES, MEASURES

Michael Gough

Translation from book Phantom Risk: Scientific Inference and the Law, MIT Press 1993


A critical review of worldwide investigations of environmental and occupational health effects due to exposures to 2,3,7,8-tetrachlorodibenzodioxin (TCDD) is presented. Initial Swedish results on extreme carcinogenicity of dioxine are compared with two series of German and American studies which do not confirm the early Swedish observations.

Cancer, birth defects, and other toxic effects are seen in animals only at doses close to those that cause overt toxic effects in adult animals. It is argued that humans have never been exposed to comparable exposure levels. Consequently, there is no convincing evidence for human cancer risk increase related to dioxin exposures.


Wiadomości Chemiczne, 1996, 50, 469.
Back   |  Home page


GLASSY METALS IN ELECTROCHEMISTRY. PASSIVITY AND ELECTROCATALYTIC PROPERTIES

Maria Janik-Czachor, Anna Wołowik

Instytut Chemii Fizycznej PAN, ul. Kasprzaka 44/52, 01-224 Warszawa


Present state of understanding the structure and the electrochemical behaviour of metallic glasses in various environments is summarized. Emphasis is placed on the experimental evidence concerning the ability to passivate, stability of the passive state of these alloys including the susceptibility to pitting, as well as on details of the characteristic features and peculiarities of these systems. The stationary behaviour, based on recent models for homogenous alloys, is discussed. The role of amorphous alloys in electrocatalysis and perspective of their application in this area are pointed out.


Wiadomości Chemiczne, 1996, 50, 497.
Back   |  Home page


UCZONY CZY NAUKOWIEC, CZYLI O PRZEŚWIADCZENIACH W NAUCE.

Przemysław Mastalerz

ul. Gliniana 23 m 17, 50-525 Wrocław



Wiadomości Chemiczne, 1996, 50, 517.
Back   |  Home page


Notatki chaotyczne. VIII. O ANALOGII W CHEMII.

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1996, 50, 521.
Back   |  Home page


THE BEGINNINGS OF PHYSICAL CHEMISTRY AT THE LVOV UNIVERSITY - BRONISŁAW LACHOWICZ AS A PHYSICAL CHEMIST

Zdzisław Ruziewicz

ul. Zielonego Dębu 23, 51-621 Wrocław


The biography of Bronisław Lachowicz (1856-1903) is outlined and his role in the development of Chemistry Department of the Lvov University during the last two decades of XIX century enhanced. Lachowicz was the first Polish university teacher reading lectures on physical chemistry. The bibliography of Lachowicz`s scientific papers is given and those concerning miscellaneous physicochemical problems are critically reviewed.


Wiadomości Chemiczne, 1996, 50, 535.
Back   |  Home page


MOLECULAR MODELLING METHODS.
Part I: BASIC TECHNIQUES AND CHALLENGING PROBLEMS

Bogdan Lesyng1, J. Andrew McCammon2

1 Zakład Biofizyki Instytutu Fizyki Doświadczalnej Uniwersytetu Warszawskiego, ul. Żwirki i Wigury 93, 02-089 Warszawa
2 Institute of Molecular Desing, Department of Chemistry, University of Huston, Huston TX 77204, USA
Interdyscyplinarne Centrum Modelowania Matematycznego i Komputerowego, ul. Banacha 2, 02-907 Warszawa


An overview is presented of computer modelling and simulation methods that play an increasing role in drug design: quantum chemical methods, molecular mechanics, molecular dynamics and Brownian dynamics. The application of molecular dynamics for the prediction of thermodynamic properties like free energy differences and binding constants is discussed. The Brownian dynamics method is presented in connection with the calculation of effective electrostatic forces using the Poisson-Boltzmann equation, which allows one to sample ligand-binding geometries and to predict the kinetics of diffusion-limited enzyme reactions. New techniques that have recently been extensively developed, such as the global energy minimization and quantum-classical dynamics methods, are also introduced. The molecular modelling methods are illustrated with selected examples.


Wiadomości Chemiczne, 1996, 50, 563.
Back   |  Home page


MOLECULAR MODELING METHODS.
Part II: PRESENT STATE AND PERSPECTIVES

Bogdan Lesyng

Interdyscyplinarne Centrum Modelowania Matematycznego i Komputerowego, ul. Banacha 2, 02-907 Warszawa
Zakład Biofizyki Instytutu Fizyki Doświadczalnej Uniwersytetu Warszawskiego, ul. Żwirki i Wigury 93, 02-089 Warszawa


The short review supplements the previous article which is a translated version of the paper: B. Lesyng and J.A. McCammon, Molecular modeling methods. Basic techniques and challenging problems. Pharmac. Ther., 1994, 60, 149-167. The role of molecular modeling in the framework of computer simulation techniques in natural sciences is shortly discussed here. Supplementary literature on a broad class of algorithms and on new computer technologies is given.


Wiadomości Chemiczne, 1996, 50, 587.
Back   |  Home page


APPLICATION OF TOTAL RELAXATION FIELD OF 1-H NOE AND MOLECULAR MODELING TO STEREOCHEMICAL STUDIES OF ORGANIC COMPOUNDS

Lech Kozerski, Robert Kawęcki, Piotr Krajewski

Instytut Chemii Organicznej, Polska Akademia Nauk, ul. Kasprzaka 44/52, 01-224 Warszawa


Application of the title method is presented for searching the conformational space in small flexible molecules for assignment of relative configuration of stereogenic centers and for recognition of intermolecular interactions in solution.


Wiadomości Chemiczne, 1996, 50, 591.
Back   |  Home page


KINETICS OF FAST BIMOLECULAR REACTIONS STUDIED BY FLUORESCENCE QUENCHING.
Part I: THEORY OF THE TRANSIENT EFFECT.

Marek Sikorski

Zakład Fotochemii, Wydział Chemii, Uniwersytet im. A. Mickiewicza, ul. Grunwaldzka 6, 60-780 Poznań


Time-resolved fluorescence quenching is an important method for studying diffusion-controlled reactions and in addition Single Photon Counting (SPC) techniques give data curves with high precision. A particularly important case is a diffusion-limited reaction with a time-dependent reaction rate coefficient, which in the initial stages is described by nonstationary solutions of the diffusion equations. In this paper an explicit form of an equation for the reaction rate coefficient, k(t), is given along with functions - obtained by using these equations - describing the decay of donor fluorescence in the presence of a quencher, I(t). It is also demonstrated how the dynamics of bimolecular processes may be studied by using dynamic measurements I(t) and/or Stern-Volmer kinetic curves.


Wiadomości Chemiczne, 1996, 50, 607.
Back   |  Home page


APPLICATION OF THE HAMMETT EQUATION TO PROTON TRANSFER REACTIONS FOR POLYFUNCTIONAL AND TAUTOMERIC COMPOUNDS

Ewa Daniela Raczyńska

Katedra Chemii Ogólnej, Szkoła Główna Gospodarstwa Wiejskiego, ul. Rakowiecka 26/30, 02-528 Warszawa


Possibilities of application of the Hammett equation to the study of proton transfer equilibria for polyfunctional and tautomeric systems are presented and illustrated.


Wiadomości Chemiczne, 1996, 50, 625.
Back   |  Home page


Notatki chaotyczne. IX. INTUICJE I ILUMINACJE.

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1996, 50, 653.
Back   |  Home page


WOMEN IN SCIENCE
IN THE SCIENTIFIC CIRCLE OF MARIA SKŁODOWSKA-CURIE

Maria Cieślak-Golonka

Instytut Chemii Nieorganicznej i Metalurgii Pierwiastków Rzadkich, Politechnika Wrocławska, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław


This article traces the life and work of seven women, i.e. H. Brooks, E. Gleditsch, M.Sybil Leslie, E. Ramstedt, J. Szmidt, I. Joliot-Curie and A. Dorabialska working in Maria Skłodowska-Curie Laboratory and shows the role of her as supervisor.


Wiadomości Chemiczne, 1996, 50, 671.
Back   |  Home page


CRYSTAL STRUCTURE REFINEMENT FROM POWDER DATA - THE RIETVELD METHOD

Joanna Lutosławska-Rogóż, Stanisław A. Hodorowicz

Zakład Krystalochemii i Krystalofizyki, Wydział Chemii, Uniwersytet Jagielloński, ul. Ingardena 3, 30-060 Kraków


The Rietveld method - a tool for crystal structure refinement from powder X-ray data - is presented. An example illustrating the procedure of Rietveld refinement of magnesium hexaaqua bromate structure is also included.


Wiadomości Chemiczne, 1996, 50, 687.
Back   |  Home page


DIFFERENCES IN CHEMICAL BEHAVIOUR OF ISOTOPES AS EXEMPLIFIED BY 238U AND 235U

Tomasz Mioduski

Instytut Chemii i Techniki Jądrowej, ul. Dorodna 16, 03-195 Warszawa


Some theoretical and technological aspects of the chemical uranium enrichment are discussed. The CHEMEX liquid-liquid extraction, Asahi (ACEP) ion-exchange, and MLIS and AVLIS laser methods are presented. A careful analysis of the influence of the odd neutron number of isotope on its chemical behaviour (the even-odd effect) has brought us to the conclusion that there must exist an opposite effect for nuclids with extra stable nuclei. This hypothesis is to be verified for 14260Nd, 20882Pb, and 50Sn vs other isotopes of these "magic" nuclids.


Wiadomości Chemiczne, 1996, 50, 701.
Back   |  Home page


ANION RECEPTORS

Wojciech Wróblewski, Zbigniew Brzózka

Zakład Chemii Analitycznej, Wydział Chemiczny Politechniki Warszawskiej, ul. Noakowskiego 3, 00-664 Warszawa


In this publication the physicochemical parameters of anions having an influence on the selective anion complexation by receptor molecules were described in detail. The value of hydration energy, by charge distribution in molecule, Lewis acid-base character (as well as Pearson`s hardness) and the anion size were chosen as the most important properties of anions. The types of selective anion recognition by receptor molecules and possible chemical interactions between "host" and "guest" were discussed. The main part of this work contains a literature review concerning anion selective receptors, divided on four groups based on different interaction with ion (electrostatic, hydrogen bonding, coordination and covalent).


Wiadomości Chemiczne, 1996, 50, 721.
Back   |  Home page


WAR GASES IN THE SOUTHERN BALTIC SEA

Krzysztof Korzeniewski

Instytut Oceanografii, Uniwersytet Gdański, al. Marsz. J. Piłsudskiego 46, 81-378 Gdynia


The paper describes results and research done on the influence of the war gases, dumped in the Southern Baltic Sea between 1945 and 1948, on people who live and work in this area.


Wiadomości Chemiczne, 1996, 50, 745.
Back   |  Home page


ANALYSIS OF STRUCTURAL AND ENERGETIC PROPERTIES OF MICROPOROUS CARBONACEOUS ADSORBENTS

Jerzy Choma1, Mieczysław Jaroniec2

1Instytut Chemii Wojskowej Akademii Technicznej, ul. S. Kaliskiego 2, 01-489 Warszawa
2Separation and Surface Science Center, Department of Chemistry, Kent State University, Kent, Ohio 44-242, USA


Advanced methods of characterization of structural and energetic properties of microporous carbonaceous adsorbents are reviewed. The porous structure of carbonaceous adsorbents, its creation, classification, and influence on the sorption properties is discussed. A main focus was placed on molecular adsorption and its use for studying solid adsorbents. It was shown that the structural heterogeneity of carbonaceous adsorbents can be characterized in terms of the pore volume distribution, which can be obtained by Jaroniec-Choma, Horvath-Kawazoe or density functional theory methods. However, the energetic heterogeneity of these adsorbents can be characterized in terms of the adsorption energy distribution obtained by the condensation approximation method or regularization methods. These methods were illustrated by using our experimental results and theoretical calculations for carbonaceous adsorbents.


Wiadomości Chemiczne, 1996, 50, 759.
Back   |  Home page


CATALYTIC CONVERSION OF METHANE TO ETHYLENE BY OXIDATIVE COUPLING

Andrzej Machocki

Zakład Technologii Chemicznej, Wydział Chemii, Uniwersytet Marii Curie-Skłodowskiej, pl. Marii Curie-Skłodowskiej 3, 20-031 Lublin


The possibilities of direct conversion of methane to ethylene in the catalytic process of oxidative coupling have been presented. The literature data and the autor`s own results have been taken into consideration. The paper was presented at the conference "Natural Gas for Chemical Technology", Puławy, June 1-2, 1995.


Wiadomości Chemiczne, 1996, 50, 789.
Back   |  Home page


Notatki chaotyczne. X. O BŁĘDACH. NIEBEZPIECZEŃSTWA EKSTRAPOLACJI.

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1996, 50, 807.
Back   |  Home page


APPLICATIONS OF NEURAL SELF-ORGANIZING MAPS IN CHEMISTRY

Jarosław Polański

Zakład Chemii Organicznej, Instytut Chemii Uniwersytetu Śląskiego, ul. Szkolna 9, 40-006 Katowice


The architecture of the self-organizing maps and their implementations in chemistry have been reviewed. In particular the comparisons of the protein sequences, the mapping of chemical molecules and the analysis of the pollution emission sources have been illustrated. All the procedures discussed were designed successfully to form interesting and efficient methods of chemometric analysis.


Wiadomości Chemiczne, 1996, 50, 817.
Back   |  Home page


THE LINEAR MODEL OF THE CHEMICAL EQUATION

Piotr Kosztołowicz

ul. Okrzei 9/6, 25-525 Kielce


A matrix method of generating, balancing and determining the number of independent reactions has been described and discussed.


Wiadomości Chemiczne, 1996, 50, 827.
Back   |  Home page


KINETICS OF FAST BIMOLECULAR REACTIONS STUDIED BY FLUORESCENCE QUENCHING.
Part II: TRANSIENT EFFECT - COMPARISON OF THEORY WITH EXPERIMENT

Marek Sikorski

Zakład Fotochemii, Wydział Chemii, Uniwersytet im. A. Mickiewicza, ul. Grunwaldzka 6, 60-780 Poznań


The application in detection systems of a new generation of photomultipliers - micro-channel plates - at the end of the last decade enabled considerable progress in experimental studies of fast bimolecular reactions. This paper presents results of studies of fluorescence quenching partly controlled by diffusion in solutions, with particular emphasis on the transient effect. This paper also reports on previous experimental studies in which the Smoluchowski-Collins-Kimbal kinetics model with a time dependent reaction rate coefficient was applied.


Wiadomości Chemiczne, 1996, 50, 841.
Back   |  Home page


BENEFICIAL RADIATION

Zbigniew Jaworowski

Centralne Laboratorium Ochrony Radiologicznej, ul. Konwaliowa 7, 03-194 Warszawa


Adaptive biological effects of ionizing radiation occur at near natural doses. This disagrees with non-threshold relationship, which is a basis of the current radiation protection. Vast literature demonstrates that such effects, occuring at molecular, cellular and population levels, result in increased longevity and decreased cancer incidence. Exposure to lower than natural radiation causes deficiency symptoms.


Wiadomości Chemiczne, 1996, 50, 857.
Back   |  Home page


ZIRCONIUM DIOXIDE IN CATALYSIS. PROPERTIES AND APPLICATION

Andrzej Lewicki, Tadeusz Paryjczak, Jacek Rynkowski

Instytut Chemii Ogólnej i Ekologicznej, Politechnika Łódzka, ul. Żwirki 36, 90-924 Łódź


The use of zirconium compounds in catalytic systems has been growing considerably. The major interest is connected with zirconium dioxide - which in the form both of a single oxide and combined oxides - has been proved to be a very promising catalyst for various reactions. In this paper the properties and examples of application of ZrO2 as catalyst and catalyst support have been reviewed.


Wiadomości Chemiczne, 1996, 50, 879.
Back   |  Home page


BROMINE-CONTAINING OXIDATION BY-PRODUCTIONS IN WATER TREATMENT

Jacek Nawrocki, Sławoir Biłozor

Zakład Technologii Uzdatniania Wody, Wydział Chemii, Uniwersytet im. Adama Mickiewicza, ul. Drzymały 24, 60-613 Poznań


The paper is a review dealing with the problem of bromine-containing by-products formed by application of strong oxidants in water treatment technology. By-products resulting from reaction of organic and inorganic "precursors" in treated water containing bromides with strong oxidants: chlorine, ozone, chloramine and chlorine dioxide are described. The possible sources of bromide in natural waters, formation of bromine-containing by-products, health risk arising from their presence in drinking water, the technology of removal of these compounds from drinking water as well as analytical methods for their determination have been discussed.


Wiadomości Chemiczne, 1996, 50, 903.
Back   |  Home page


SOLID STATE NMR STUDIES OF THE STRUCTURE AND DYNAMICS OF THE PHOSPHOROORGANIC DICHALCOGENIDES

Marek J. Potrzebowski

Centrum Badań Molekularnych i Makromolekularnych, Polska Akademia Nauk, ul. Sienkiewicza 112, 90-362 Łódź


Solid state NMR spectroscopy was used to study the structure and dynamics of phosphoroorganic dichalcogenes with general formula RR`P(S)XX(S)PRR` where X = S, Se. X-ray diffraction has revealed that the conformation of (S)PXXP(S) backbone depends on R, R` substituents and can adopt anti-anti, anti-syn, and syn-syn geometry. The interaction between p-electrons of X atoms and empty dxz and dyz orbials of phosphorus has influence on geometry of S = P-X unit. For anti-anti conformation the P-X distances are shorter and S = P-X angles smaller compared to syn-syn conformation. The changes of local environment of phosphorus were recognized by 31P CP/MAS experiment. The investigation of series of bis(organothiophosphoryl) disulfides has allowed to establish the relationship between 31P chemical shift parameters; anisotropy D, asymmetry h , principal elements of chemical shift tensor d and molecular structure of S=P-S-S-P=S fragment.

The question of correlation between the number of resonances in the isotropic part of spectrum and molecular symmetry established by single-crystal X-ray diffraction was discussed. Moreover, the 31P CP/MAS nad 77Se CP/MAS experiments for phosphoroorganic dichalcogenides were used to study different polymorphic forms, inclusion complexes, solvates as well as phase transitions below melting point. The deuterated solvents occluded in the crystal lattice of inclusion complexes were investigated by means of 1H-2H CP/MAS NMR technique.

The line-sharpe analysis of the "Pake doublet" for static 2H experiment and 13C CP/MAS technique were employed to investigation of the intermolecular dynamics of aliphatic and/or aromatic groups directly bonded to phosphorus.


Wiadomości Chemiczne, 1996, 50, 925.
Back   |  Home page


Notatki chaotyczne. XI. O BŁĘDACH. BŁĘDY SZTUKI.

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1996, 50, 951.
Back   |  Home page

Back   |     Back to HomePage
   T. Cukierda, last changes: