Wiadomości Chemiczne

Wiadomości Chemiczne, 1997, 51.

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  1. Alfred Nobel and his greatest invention
    Andrzej Kasperowicz

  2. Heterofullerens
    Andrzej Huczko

  3. Conformational analysis of benzocyclononene heterocyclic analogues
    Barbara Rys

  4. The methods of N-alkylamino acids synthesis and their significance in the peptide chemistry
    Kazimierz Wiśniewski

  5. Chromatographic analysis of lipids occuring in biological membranes
    Stanisława Koronkiewicz, Bogusław Buszewski

  6. Notatki chaotyczne. XII. Muratorzy XX wieku
    Ignacy Z. Siemion

  7. Nobel Prize 1997 of chemistry: Fullerens
    Jacek Gliński

  8. Rational design of herbicides - inhibitors of amino acid biosynthesis
    Paweł Kafarski

  9. Proctolin - a natural insect neuropeptide
    Danuta Konopińska

  10. Some aspects of nitric oxide chemistry and biochemistry
    Grażyna Stochel, Marek Pawelec, Zofia Stasicka

  11. Speciation analysis of biological samples
    Adam Hulanicki

  12. What is the origin of dynamite ?
    Andrzej Kasperowicz

  13. Reactions of carboxylic acids with oxiranes
    Agnieszka Bukowska, Wiktor Bukowski, Henryk Galina

  14. Granice poznania w oczach chemika
    Lucjan Sobczyk

  15. Notatki chaotyczne. XIII. O błędach. Błędy pychy
    Ignacy Z. Siemion

  16. XI International symposium on Organosilicon Chemistry. Montpellier, wrzesień 1996
    Jacek Guliński

  17. Biological and chemical aspects of the trifluoromethyl group
    Wojciech Dmowski

  18. Enzymatic synthesis of optically pure amino acids a-amino acids
    Ewa Żymańczyk-Duda, Barbara Lejczak

  19. Optical basicity of inorganic oxide glasses
    Andrzej M. Kłonkowski

  20. Non-methane hydrocarbons (NMHC) in the ambient air. Part I
    Magdalena Kurdziel, Elżbieta Szczepaniec-Cięciak

  21. Inorganic areogels - non-conventional supports and catalysis of heterogeneous processes
    Barbara Pniak, Jerzy Walendziewski, Marek Stolarski, Mieczysław Steininger

  22. Photochemistry in researches of the old-time polish scientists. Part I: XIXth century
    Zdzisław Ruziewicz

  23. Notatki chaotyczne. XIV. Rozmyślania nad nowym podręcznikiem chemii organicznej pióra Przemysława Mastalerza
    Ignacy Z. Siemion

  24. Pamięci Profesor Marii Szymańskiej (w 75 rocznicę urodzin)
    J.Stradins, A.Andersons, L. Leite (Łotwa), M. Czerwenka (Polska)

  25. Międzynarodowy Kongres Ekologiczny. Woroneż, Rosja, 22-28 IX 1996 r.
    Stanisław Kopacz

  26. 30 Years of Institute of Low Temperature and Structure Research, Polish Academy of Sciences
    Paweł E. Tomaszewski

  27. My adventure with low temperatures
    Roman S. Ingarden

  28. Primaeval history and origin of the Institute
    Kazimierz Łukaszewicz

  29. Middle ages of the Institute
    Jan Klamut

  30. The Institute today
    Józef Sznajd

  31. Metal-to-insulator or metal-to-semiconductor transitions in lanthanide hydrides
    , Henryk Drulis

  32. Nanostructured aluminum hydroxides and oxides
    Mirosław Zawadzki

  33. Spectroscopic properties of alkali halides doped with Cr(CN)63- ion
    Krzysztof Hermanowicz

  34. Strukture transformation in BiLa2O4,5 + d
    Roman Horyń, Marek Wołcyrz, Zbigniew Bukowski

  35. The crystal structure and phase transitions of protonic conductors (NH4)3H(SeO4)2
    Adam Pietraszko

  36. Crystal growth and magnetic anisotropy of resistivity of U3X4 pnictides
    Piotr Wiśniewski, Zygmunt Henkie

  37. Radon
    Zbigniew P. Zagórski

  38. Relativistic effects in atomic and molecular systems
    Szczepan Roszak, Henryk Chojnacki

  39. 5-HT3 Serotonin receptors
    Stanisław Misztal, Maria H. Paluchowska

  40. Domino reactions in organic synthesis
    Krystyna Bogdanowicz-Szwed, Małgorzata Krasodomska, Wojciech Krasodomski

  41. Anti-juvenile hormone agents
    Czesław Wawrzeńczyk

  42. Analysis of trace elements in biological samples -selected problems
    Wiesław Żyrnicki, Jolanta Borkowska-Burnecka

  43. Solubility parameters - determination and application
    Adam Voelkel, Jacek Fall

  44. Notatki chaotyczne. XV. O Jakubie Natansonie
    Ignacy Z. Siemion

  45. VI Poznańskie Konwersatorium Analityczne. "Nowoczesne Metody Przygotowania Próbek i Oznaczania Śladowych Ilości Pierwiastków"
    Jan Szymanowski

  46. International Symposium on Photodynamic Therapy
    Piotr Ziółkowski

  47. Biogeochemistry of iron and mangenese
    Zygmunt Sadowski

  48. Properties of singlet oxygen as a strong enophile
    Wojciech J. Kinart, Cezary M. Kinart, Iwona M. Kozak-Michałowska, Ewa Śnieć

  49. Topological indices and their significance in chromatographic investigations
    Alina Pyka

  50. Immunochemical methods of triazine pesticides determination in soil, water and food
    Joanna Masłowska, Alina Owczarek, Joanna Leszczyńska

  51. Topological systems for structural representation of molecules
    Jarosław Tomczak

  52. Nonmethane hydrocarbons (NMHC) in the ambient air . Part I: analytical problems
    Magdelena Kurdziel, Elżbieta Szczepaniec-Cięciak

  53. Notatki chaotyczne. XVI. O błędach. Błędy Pokory
    Ignacy Z. Siemion

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ALFRED NOBEL AND HIS GREATEST INVENTION

Andrzej Kasperowicz

Instytut Chemii Uniwersytetu Warszawskiego, Filia w Białymstoku, al. Piłsudskiego 11/4, 15-443 Białystok


Alfred Nobel`s life, the selections and the nominations of candidates, presentation of the Nobel Prizes and administration of the Nobel Foundation are described in this paper.


Wiadomości Chemiczne, 1997, 51, 1.
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HETEROFULLERENES

Andrzej Huczko

Pracownia Chemii Plazmy, Wydział Chemii, Uniwersytet Warszawski, ul. Pasteura 1, 02-093 Warszawa


Since the discovery of fullerenes, efforts have been made to synthesize both endohedral and exohedral compounds. However, there is a third possibility when a "guest" atom or molecule (e.g. B, N, BN, ...) is bound as a part of the carbon cage. This new class of "networked" fullerenes is presented and their expected properties and possible synthesis routes are discussed.


Wiadomości Chemiczne, 1997, 51, 27.
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CONFORMATIONAL ANALYSIS OF BENZOCYCLONONENE HETEROCYCLIC ANALOGUES

Barbara Rys

Zakład Chemii Organicznej, Wydział Chemii, Uniwersytet Jagielloński
30-060 Kraków, ul. Ingardena 3


The results of own research on the conformational analysis of the following heterocyclic systems: 1,4,5,7-tetrahydro-3H-2,6-benzodithionin and -diselenin, 1,2,6,7-tetrahydro-4H-3,5-benzodioxonin, and 7,8-dihydro-6H-dibenzo [f.h][1.5] dioxonin have been described. Analysis of 1H, 13C and 77Se DNMR spectra allowed to establish their static and dynamic conformational behaviour. These results are compared with those from calculations and X-ray studies.


Wiadomości Chemiczne, 1997, 51, 49.
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THE METHODS OF N-ALKYLAMINO ACIDS SYNTHESIS AND THEIR SIGNIFICANCE IN THE PEPTIDE CHEMISTRY

Kazimierz Wiśniewski

Zespół Chemii Aminokwasów i Peptydów, Wydział Chemii, Uniwersytet Gdański, ul. Sobieskiego 18, 80-952 Gdańsk


N-alkylamino acids are an important group of organic compounds. Numerous peptides containing N-alkylamino acids and showing wide range of biological activity have been isolated from natural sources. Some analogues of naturally occuring peptides with N-alkylated amide bond were used in structure-activity relationship investigations as well as for conformational studies. N-alkylation of the peptide bond enhances its stability against enzymatic hydrolysis. Therefore, the synthesis of N-alkyl amino acids and their derivatives appears to be a challenge for organic chemists. The modern methods of preparation of these compounds have been reviewed. Selective alkylation of diamino acids has been also described.


Wiadomości Chemiczne, 1997, 51, 63.
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CHROMATOGRAPHIC ANALYSIS OF LIPIDS OCCURRING IN BIOLOGICAL MEMBRANES

Stanisława Koronkiewicz1, Bogusław Buszewski2

1Instytut Chemii Uniwersytetu Warszawskiego, Filia w Białymstoku, al. J.Piłsudskiego 11/4, 15-443 Białystok
2Zakład Chemii Środowiska, Wydział Chemii, Uniwersytet Mikołaja Kopernika, ul. Gagarina 7, 87-100 Toruń


Different chromatographic methods used for determination of lipids isolated from natural biological membranes have been described. A special attention has been paid to the sample preparation, and problems connected with detection during high performance liquid chromatography (HPLC) analysis. A separate part of this review is devoted to the choice of the HPLC seperation conditions (packing, mobile phase composition) in phospholipid analysis. Moreover, there have been proposed potential possibilities of application of some representants belonging to the lipids as a stationary phase with specific selective properties to the chromatography and related techniques (CZE - capillary zone electrophoresis, SPE - solid phase extraction, etc.) have been proposed.


Wiadomości Chemiczne, 1997, 51, 81.
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Notatki chaotyczne. XII. MURATORZY XX WIEKU

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1997, 51, 97.
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NOBEL PRIZE 1996 OF CHEMISTRY: FULLERENES

Jacek Gliński

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



Wiadomości Chemiczne, 1997, 51, 111.
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RATIONAL DESIGNE OF HERBICIDES-INHIBITORS OF AMINO ACID BIOSYNTHESIS

Paweł Kafarski

Instytut Chemii Organicznej, Biochemii i Biotechnologii Politechniki
Wrocławskiej, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław
and Instytut Chemii Uniwersytetu w Opolu, ul. Oleska 32, 45-052 Opole


The design and development of new herbicides is increasingly concerned with enzyme inhibitors. Very considerable progress has been made in this area over the last twenty years, especially with the advent of herbicides blocking essential amino acids biosynthesis. These inhibitors would be limited in activity to the organisms possessing the target biochemical pathways, namely plants and microorganisms. The review describes three herbicide classes which have amino acid biosynthesis as their site of action: inhibitors of biosynthesis of aromatic amino acids, inhibitors of branched-chain amino acid pathway and inhibitors of ammonia assimilation.


Wiadomości Chemiczne, 1997, 51, 125.
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PROCTOLIN - A NATURAL INSECT NEUROPEPTIDE

Danuta Konopińska

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


In the present paper the literature data on the synthetic, biological, and conformational studies on insect neuropeptide proctolin (Arg-Tyr-Leu-Pro-Thr) and its analogues are summarized. The paper covers proctolin and its 80 analogues modified in positions 1-5, cycloanalogue as well as analogues with the truncated or elongated peptide chain. The presented peptides were bioassayed by different methods, e.g. by studies of myotropic activities in several insect species in vitro and by behaviour in rats in vivo. Basing on these data structure-activity relationship is discussed.


Wiadomości Chemiczne, 1997, 51, 145.
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SOME ASPECTS OF NITRIC OXIDE CHEMISTRY AND BIOCHEMISTRY

Grażyna Stochel, Marek Pawelec, Zofia Stasicka

Wydział Chemii, Uniwersytet Jagielloński, ul. Ingardena 3, 30-060 Kraków


One of the most exciting findings in biological chemistry during last few years was discovery that nitric oxide, potentially toxic molecule, is responsible for astonishing range of physiological processes in human organism. The integration of nitric oxide chemistry with current perspectives of its biology illuminates many aspects of NO biochemistry. Some of these aspects are presented and discussed in this paper.


Wiadomości Chemiczne, 1997, 51, 163.
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SPECIATION ANALYSIS OF BIOLOGICAL SAMPLES

Adam Hulanicki

Wydział Chemii, Uniwersytet Warszawski, ul. Pasteura 1, 02-093 Warszawa


One of the most important aspects of contemporary analytical chemistry is speciation analysis, in particular related to biological objects. A number of conferences and specialized publications have been devoted to this subject. Speciation analysis requires a specific approach which presents a new challenge to analysts. In particular important aspects are connected with sampling, the use of coupled analytical techniques, consisting of a separation step and a sensitive detection and with securing high quality of analytical results.


Wiadomości Chemiczne, 1997, 51, 189.
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WHAT IS THE ORIGIN OF DYNAMITE ?

Andrzej Kasperowicz

Instytut Chemii Uniwersytetu Warszawskiego,Filia w Białymstoku, Al. Piłsudskiego 11/4, 15-443 Białystok
Present address:
Department of Environmental Sciences, University of Plymouth,
Drake Circus, Plymouth, Devon PL4 8AA, United Kingdom


The history of the development of the first explosives with particular emphasis on dynamite is presented in this paper.


Wiadomości Chemiczne, 1997, 51, 205.
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REACTIONS OF CARBOXYLIC ACIDS WITH OXIRANES

Agnieszka Bukowska, Wiktor Bukowski, Henryk Galina

Wydział Chemiczny, Politechnika Rzeszowska im. I. Łukasiewicza,
Al. Powstańców W-wy 6, 35-959 Rzeszów


The literature on the reaction of carboxylic acids with oxiranes has been reviewed. The kinetics and mechanism of the reaction as well as regioselectivity of oxirane ring opening are discussed and related to the type of catalysts used. The groups of catalyst types are characterized. Directions of practical applications of the products: hydroxyalkyl esters, are specified.


Wiadomości Chemiczne, 1997, 51, 217.
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GRANICE POZNANIA W OCZACH CHEMIKA

Lucjan Sobczyk

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



Wiadomości Chemiczne, 1997, 51, 235.
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Notatki chaotyczne. XIII. O BŁĘDACH. BŁĘDY PYCHY

Ignacy Z. Siemion

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


Wiadomości Chemiczne, 1997, 51, 243.
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XI INTERNATIONAL SYMPOSIUM ON ORGANOSILICON CHEMISTRY. Montpellier, wrzesień 1996

Jacek Guliński

-


Wiadomości Chemiczne, 1997, 51, 249
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BIOLOGICAL AND CHEMICAL ASPECTS OF THE TRIFLUOROMETHYL GROUP

Wojciech Dmowski

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


The trifluoromethyl group is a unique substituent which, when present in an organic molecule, affects its chemical, physical and biological properties. The relationship between physical parameters of the CF3 group and biological activity of trifluoromethyl derivatives is discussed and their applications as drugs, agrochemicals, dyes and polymers are exemplified. Methods of trifluoromethylation of organic compounds, chemistry of the CF3 group and its influence on the reactivity of neighbouring atoms and groups are reviewed. Syntheses of selected trifluoromethyl analogues of natural compounds are also described.


Wiadomości Chemiczne, 1997, 51, 263.
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ENZYMATIC SYNTHESIS OF OPTICCALY PURE a-AMINO ACIDS

Ewa Żymańczyk-Duda, Barbara Lejczak

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


One of the attractions of using enzymes for chemical synthesis is the control of stereochemistry, which results in optically active products. The other advantage is that only minimal protection-deprotection steps are involved. The possibility of using enzymes in non-aqueous media or biphasic mixtures of water and organic solvent increases the number of possible substrates which can be used. The main disadvantages of enzymes as catalysts in chemical syntheses are their rather high price, low stability at higher temperatures and extreme pH values. These, however, can be omitted or, at least, minimized by the use of crude preparations, by proper immobilization techniques or the use of the whole cells of microorganisms overproducing the desired enzyme. Enzymatic methods of the synthesis of the products of defined stereochemistry become more and more popular among chemists, being the most widely used for the preparation of optically pure a-amino acids. These compounds are finding increasing utility in the synthesis of pharmaceuticals, production of agricultural products, food industry and material science. Selective synthesis of pure enantiomers of a-amino acids can be achieved by means of the enzymatic kinetic resolution of the racemic mixtures of D,L a-amino acids or its derivatives (namely by estrification, transestrification, acylation, oxidative deamination or hydrolysis) or enantiomerically catalysed condensation of achiral substrates.
The purpose of this article is to review enzymatic methods used in the synthesis of a-amino acids in their optically active form and to present the most representative examples of this approach.


Wiadomości Chemiczne, 1997, 51, 293.
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OPTICAL BASICITY OF INORGANIC OXIDE GLASSES

Andrzej M. Kłonkowski

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


The relationship between electron donor power and electronic polarisability of oxide (-2) in somewhat indirect, and a more obvious method of measuring the electron donor power is to insert into material a "probe" which will respond directly to the donation of negative charge (see Fig.1) [5]. Such measurements can be made by using metal ions which exhibit the orbital expansion (nepheloauxetic) effect [19,20], particularly ions with s2 outer configuration such as Tl+, Pb2+ or Bi3+ [21,22]. This effect is illustrated in Fig.2 and applied to measure experimental optical basicity D (Eq. (5)) [23]. For many alkali and alkaline earth silicates, phosphates, borates (usually as glasses), and also certain other compounds D can be calculated. Among the parameters in the expression of D is the so-called "basicity moderating parameter", g [27,28]. It is noted that g increases roughly in line with electronegativity, except for the transition elements (cf. Fig. and Eq.(6)). Equation (8) is a general expression for the theoretical optical basicity, Dcal, of a system consisting of many oxide components. Hence Dcal is an ideal measure of the Lewis basicity, therefore it may be used as an indicator of structural changes in a vitreous system if contribution of one of the oxide components increases (Fig.4)[14]. Very often the basicity orders of various oxide systems show changes of their physical parameters (see Figs 5-9) [12, 13, 15, 16, 54].

On the other hand, experimental measures of the basicity, such as refractivity of the oxide species, Ro2- (Eq. 10) and so called Imagawa`s basicity, Gp O (Eq. (17) [40], are calculated. The former one is a measure of the basicity of all kinds of oxygen atoms in oxide systems and the latter measures the basicity of non-bridging oxides. Correlations optical basicity Dcal vs refractivity Ro2- as well Dcal vs Imagawa`s basicity Gp are illustrated in Figs 10 and 13, respectively [15, 16, 55]. Non-monotonic curves of the correlations show structural changes, as in sodium aluminosilicate vitreous system (Fig. 11) [14], or the mixed alkali effect in vitreous aluminosilicates (Figs 12 and 15) [12, 13, 54].


Wiadomości Chemiczne, 1997, 51, 313.
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NON-METHANE HYDROCARBONS (NMHC) IN THE AMBIENT AIR. Part I

Magdalena Kurdziel, Elżbieta Szczepaniec-Cięciak

Wydział Chemii, Uniwersytet Jagielloński, ul. R.Ingardena 3, 30-060 Kraków


A review of literature regading tropospheric non-methane hydrocarbons (NMHC) C2-C10 has been elaborated. Their natural and anthropogenic sources, abundance in the atmospheric air together with the examples of concentration levels in different places (urban, rural, remote areas) have been presented. The impact of various factors (meteorological conditions, sources, etc.) on the changes of NMHC concentrations in the air has been briefly discussed.


Wiadomości Chemiczne, 1997, 51, 336.
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INORGANIC AEROGELS - NON-CONVENTIONAL SUPPORTS AND CATALYSTS OF HETEROGENEOUS PROCESSES

Barbara Pniak, Jerzy Walendziewski, Marek Stolarski, Mieczysław Steininger

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


Aerogels are a very specific class of solids. They differ from homologue xerogels very much, as far as their physico-chemical and catalytic properties are taken into account. Aerogels are prepared by sol-gel method followed by supercritical drying. It is possible to regulate the properties by change of preparation parameters. The influence of the conditions of sol-gel reaction as well as the drying step on the physico-chemical properties of some inorganic aerogels has been presented. The catalytic activity of different inorganic aerogels has been also described.


Wiadomości Chemiczne, 1997, 51, 365.
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PHOTOCHEMISTRY IN RESEARCHES OF THE OLD-TIME -POLISH SCIENTISTS. Part I: XIXth Century

Zdzisław Ruziewicz

ul. Zielonego Dębu 23, 51-621 Wrocław


The contributions to photochemistry, published by Polish scientists during the XIXth century, are reviewed. It is presumed that the first photoreduction of chromium(VI) oxide had been performed by Jędrzej Śniadecki, not later than 1800. The merit of Bronisław Radziszewski, as the forerunner of photosubstitutions in aromatic series (in 1868), is pointed out. The achievements of Julian Schramm (photohalogenations), B. Radziszewski (chemiluminescence of organic compounds) and Ernest Bandrowski (crystalloluminescence) in last two decades of the XIXth century are emphasized.


Wiadomości Chemiczne, 1997, 51, 383.
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Notatki chaotyczne. XIV. ROZMYŚLANIA NAD NOWYM PODRĘCZNIKIEM CHEMII ORGANICZNEJ PIÓRA PRZEMYSŁAWA MASTALERZA

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1997, 51, 411.
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PAMIĘCI PROFESOR MARII SZYMAŃSKIEJ (w 75 rocznicę urodzin)

J.Stradins, A.Andersons, L. Leite (Łotwa), M. Czerwenka (Polska)

-


Wiadomości Chemiczne, 1997, 51, 419.
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MIĘDZYNARODOWY KONGRES EKOLOGICZNY. Woroneż, Rosja, 22-28 IX 1996 r.

Stanisław Kopacz

-



Wiadomości Chemiczne, 1997, 51, 427.
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30 YEARS OF INSTITUTE OF LOW TEMPERATURE AND STRUCTURE RESEARCH, POLISH ACADEMY OF SCIENCES

Paweł E. Tomaszewski

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


Wiadomości Chemiczne, 1997, 51, 435.
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MY ADVENTURE WITH LOW TEMPERATURES

Roman S. Ingarden

Instytut Fizyki, Uniwersytet Mikołaja Kopernika, ul. Grudziądzka 5/7, 87-100 Toruń


Wiadomości Chemiczne, 1997, 51, 443
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(30 years of Institute of Low Temperature and Structure Research, Polish Academy of Sciences)

PRIMAEVAL HISTORY AND ORIGIN OF THE INSTITUTE

Kazimierz Łukaszewicz

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


(30 years of Institute of Low Temperature and Structure Research, Polish Academy of Sciences)


Wiadomości Chemiczne, 1997,51, 451.
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MIDDLE AGES OF THE INSTITUTE

Jan Klamut

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


(30 years of Institute of Low Temperature and Structure Research, Polish Academy of Sciences)


Wiadomości Chemiczne, 1997, 51, 461.
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THE INSTITUTE TODAY

Józef Sznajd

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


(30 years of Institute of Low Temperature and Structure Research, Polish Academy of Sciences)

Wiadomości Chemiczne,.1997, 51, 477.
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METAL-TO-INSULATOR OR METAL-TO-SEMICONDUCTOR TRANSITIONS IN LANTHANIDE HYDRIDES

Henryk Drulis

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


The phenomenon of the metal-to-insulator or metal-to-semiconductor transitions induced by changes in chemical composition of lanthanide hydrides is described. For the first time such behaviour has been discovered by Staliński in 1957 [1] in lanthanium-hydrogen system (see Fig. 1). Unfortunately, his bulk samples as a rule fall apart into powder severely limiting electrical and optical measurements. After 40 years, in 1996, the group of scientists from University of Amsterdam in a brilliant experiments showed the metal-to-semiconductor transition in the yttrium-hydrogen system. Working with a compact sample (thin films) of metal they performed the first real time visual observation of the transition from an yttrium metal to a semiconductor hydride of YH3. The YHx film changes from a shining mirror (YH2) to yellowish transparent window of YH3. It can be switched quickly, reversibly and without deterioration of the film. The changes in properties of YHx as a function of x have been obtained by subjecting a 500 nm thick film of Y (with a 20nm Pd protective layer) to 105 Pa of hydrogen gas at the room temperature. To investigate the properties of YHx film for 0< x < 2.86 the electrical resistivity and light transmission measurements (1 eV < Eph < 3.2 eV) have been on-line performed during hydrogen absorption (see Fig. 3).

In this review the most likely electronic band structure scheme important for the understanding of the basic features of the metalhydrides is also presented (see Fig. 2).

The spectacular changes in optical properties from perfectly refllecting pure yttrium into an essentially non-reflecting and transparent YH2.86 film might lead to new technological applications of rare earth metal-hydride film.


Wiadomości Chemiczne, 1997, 51, 491.
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NANOSTRUCTURED ALUMINUM HYDROXIDES AND OXIDES

Mirosław Zawadzki

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


The paper describes methods of preparation of aluminum hydroxides and oxides with nanosized particles of different morphology.

Fibrillar ALOOH is prepared by autoclaving basic aluminum salts or aluminum hydroxides solutions in the presence of acids under hydrothermal conditions (at elevated temperatures for appropriate times). The synthesis conditions which principally affect the character of the product obtained are: acid used and its concentration, concentration of aluminum and its ratio to acid, operating temperature and temperature-time relation. An unusual characteristic of such products is that the ultimate particles consist of fibrills about 5 nm in diameter and over 100 nm long, each consisting of a crystal of boehmite. Fibrillar alumina have properties of high surface area with attendant adsorptive and ion exchange characteristics, chemical stability, refraction nature and good film-formation properties.

The raw materials for preparation of aluminum hydroxides with quasi-spheroidal particles about 3-100 nm in diameter are aluminum alkoxides. During the process, alkoxides are hydrolyzed and the resultant hydroxide is peptized to a clear sol. The sol then must be gelled and pyrolyzed to 500 oC to obtain the porous transparent Al2O3. Other properties are: a linear thermal expansion, capability of being formed as thin films or in bulk and thermal stability up to ~ 1200 oC at which temperature in nondestructively converts to a-Al2O3.

Nonstructured aluminum hydroxides and oxides can be also prepared as a result of rehydration of active transition aluminas. Transition aluminas are obtained by fast calcination of gibbsite at temperatures up to 800 oC. As a consequence of fast calcination, carred out in less than 3 s, a highly amorphous product is obtained which is a mixture of aluminum oxides (r-, c-, g-) and boehmite. That product can be easily rehydrated with simultaneous changes in particle morphology and phase composition. By selecting appropriate rehydration parameters, i.e., temperature and time, characteristic particle structure - in a form of needles and plates - can be obtained. After drying and calcining, aluminum oxides with increased specific surface and decreased bulk density can be produced. The particle morphology is conserved after calcination at temperatures up to 1000 oC.

The nanocrystalline aluminum materials form mechanically and thermally stable systems that can be obtained as highly dispersed powders, thin films or solids. They are interesting materials for preparation of active matrixes - inorganic as well as organic components can be easily incorporated to such systems. Therefore composite materials with controlled structures on a nanostructure level can be achieved.


Wiadomości Chemiczne, 1997, 51, 499.
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SPECTROSCOPIC PROPERTIES OF ALKALI HALIDES DOPED WITH Cr(CN)63- ION

Krzysztof Hermanowicz

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


Raman scattering-, IR-, visible- and ESR-spectra have been studied for the Cr(CN)63- ion trapped in NaCl, NaBr, KCl, KBr and RbCl crystal matrices in order to elucidate its specific properties. The crystals were grown from aqueous solutions. The IR-, Raman and electron absorption spectra are discussed on the basis of possible symmetries of the dopant ion. The vibrational and vibronic assignments of the spectral frequencies were proposed. The results indicate that the complex ion is trapped in two nonequivalent symmetries, D2h and Cs, which have been identified and characterised by the < g >, E and D, of the spin Hamiltonian and D and B crystal field parameters. The D2h center represents extremely rare case with E/D very close to 1/3. The interaction between the trapped ion and associated vacancies is discussed and compared for all studied systems. The comparison of some spectroscopic parameters such as D, D, n6 and unit cell parameter of the hosts is given. In the halide series the observed parameters change almost linearly with the lattice dimension. Vibronic analysis of the emission spectra indicates that n8 mode is most efficient in the radiationless transitions of the 2Eg state.


Wiadomości Chemiczne, 1997, 51, 511.
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STRUCTURE TRANSFORMATION IN BiLa2O4,5 + d

Roman Horyń, Marek Wołcyrz, Zbigniew Bukowski

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


Formation of the fluoride-related binary oxide Bi1+xLa2-xO3-1,5x+ [(1+x)/2]V Bi has been studied under various temperature and oxygen pressure conditions. The phase covers a certain compositional interval within the Bi2O3-Bi2O5-La2O3 ternary system, being defined by the substitution parameter 0 £ x < 1/8 and the average valency of Bi ions 3 £V Bi < 5. Within this domain of homogeneity the phase can exhibit three different but closely related polymorphic forms, namely: rhombohedral, monoclinic, and triclinic. Only the monoclinic form is stable in air in the whole temperature range. The rhombohedral form transforms to the monoclinic one; most efficiently for x=0. This structure transformation is irreversible and becomes noticeable in air at, and above 900 oC. The new triclinic form (space group [P1] , a = 3,921 (1) Å, b = 4,024 (1) Å, c = 5,623 (1) Å, a= 87,62 (1)o, b= 90,32 (1)o, g= 90,09 (1)o develops from the monoclinic one when the latter is oxidized to the level given by V Bi ³+4. This process is fully reversible. Oxidation of the rhombohedral form preserves its structure type and seems not to induce any structure transformation. As in the case of the monoclinic form, the process is accompanied by an effective increase of V Bi > +4. Both oxidized forms are stable in air but not higher than up to 300-350 oC. Above this temperature they release oxygen with a maximum speed at ca 400 oC and retransform back to the appropriate starting structures.


Wiadomości Chemiczne, 1997, 51, 533.
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THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF
PROTONIC CONDUCTORS (NH4)3H(SeO4)2

Adam Pietraszko

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


A review is given of the crystals structures of (NH4)3H(SeO4)2 in all 6 phases. The structures of triammonium hydrogen selenate were determined by using X-ray method. Data were collected on Kuma-Diffraction KM-4 four-circle automatic diffractometer. The paper presents a detailed study of crystal structure of (NH4)3H(SeO4)2 at several temperature points, which is essential for understanding the nature and mechanism of phase transitions in (NH4)3H(SeO4)2 crystals. Positions of hydrogen atoms were taken from difference maps. In different phases the hydrogen bonds are arranged in different way. In phases I and II there are two-dimensional networks of H-bonds resulting in superionic conductivity. A correlation between the migration of protons in the crystal structure and the anisotropy of ionic conductivity is discussed. The dimerization of hydrogen bonds and the switching of H(SeO4)2 dimers in phases III-IV in connection with the ferroic properties of these phases are described.


Wiadomości Chemiczne, 1997, 51, 553.
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CRYSTAL GROWTH AND MAGNETIC ANISOTROPY OF RESISTIVITY OF U3X4 PNICTIDES

Piotr Wiśniewski, Zygmunt Henkie

Instytut Niskich Temperatur i Badań Strukturalnych PAN, ul. Okólna 2, 50-950 Wrocław


We have reviewed methods applied for growing single crystals of cubic U3X4 pnictides: the chemical vapor transport method (U3P4, U3As4), the modified Van Arkel method (U3Sb4) and the newly invented molten-metal-solution-evaporation method (U3Bi4). The complex magnetic structures of the uranium 3:4 compounds, non-collinear in U3P4 and U3As4, and collinear in U3Sb4 and U3Bi4, are discussed from the point of view of their non-ferromagnetic components. It is shown that the non-ferromagnetic components are not essential factors in the origin of giant magnetic anisotropies of electron transport properties of these compounds.


Wiadomości Chemiczne, 1997, 51, 571
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RADON

Zbigniew P. Zagórski

Zakład Chamii i Tachniki Radiacyjhej, Instytut Chemii i Techniki Jądrowej, ul. Dorodna 16, 03-195 Warszawa


Short review covers physics of radon formation and decay, indicating similarities to chemical kinetics of reactions with the rate changing with time. Electronic measurement of Rn concentrations is described and the technique of calibration which leads to hypothesis how much radon Maria Skłodowska-Curie has inhaled during her experiments. Chemical methods of Rn determination in the air and water are discussed, as well as biological consequences of radon intake. Still unsolved questions are listed.


Wiadomości Chemiczne, 1997, 51, 593.
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RELATIVISTIC EFFECTS IN ATOMIC AND MOLACULAR SYSTEMS

Szczepan Roszak, Henryk Chojnacki

Instytut Chemii Fizycznej i Teoretycznej, Politechnika Wrocławska, Wybrzeże Wyspiańskiego 23, 50-370 Wrocław


The relativistic effects in atoms and molecules, defined as tha differance batween quantum mechanical models assuming finite and infinite speed of light, respectively, are important mainly for malecular systems involving heavy atoms from tha lower part of the periodic table. The main relativistic corrections come from the increase of the papticle mass when its velocity approaches that of light, from the Darwin correction and spin-orbit coupling. Relativistic effects, together with specific effects coming from f oritals, lead to some irregularities in properties of elements from the lower region of the periodic table. The chemical differences of silver and gold, the existence of compounds for the sixth row elements, not observed for lighter atoms, are characteristic examples of influence of relativistic effects of chemical properties.


Wiadomości Chemiczne, 1997, 51, 615.
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5-HT3 SEROTONIN RECEPTORS

Stanisław Misztal, Maria H. Paluchowska

Zakład Chemii Leków, Instytut Farmakologii PAN, ul. Smętna 12, 31-343 Kraków


This review is concerned with the structure, localization, pharmacology and functional roles of the serotonin 5-HT3 receptor which is unique in the serotonin receptor area in being a ligand gated ion channel. The distribution of the 5-HT3-binding sites occurs in the area postrema. The presence of the 5-HT3 receptors in this part of brain is of particular interest because the area is involved in the emesis mechanism.

In the paper the structures of the selected representative ligands of 5-HT3 receptors are presented. A numbeer of selective agonists at 5-HT3 receptors have been described, including 2-methyl-5-hydroxytryptamine, m-chlorophenylbiguanidine and 2,3,5-trichlorophenylbiguanidine.

The 5-HT3 receptor antagonists have been the object of a great number of papers because of their potential applications in the treatment of schizophrenia, anxiety, drug dependency, inflammatory pain, migraine and gastrointestinal disorders. In our review this broad class of 5-HT3 receptor ligands has been divided into five groups containing fragments as follows: indol or indazol; trapane or its analogues; quinuclidine; benzamide or benzonate; and piperazine.


Wiadomości Chemiczne, 1997, 51, 623.
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DOMINO REACTIONS IN ORGANIC SYNTHESIS

Krystyna Bogdanowicz-Szwed, Małgorzata Krasodomska, Wojciech Krasodomski

Zakład Chemii Organicznej, Wydział Chemii, Uniwersytet Jagielloński, ul. Ingardena 3, 30-060 Kraków


The reactions that link several transformations together in a single synthetic step are called domino or tandem reactions. Domino reaction is a process invglving two or more bond-forming transformations which take place under the same reaction condations. According to the mechanism of the first step, one can distinguish between a cationic, anionic, radical pericyclic and transition-metal induced transformations. Combination of reactions of the same mechanism is called homo-domino reaction, whareas a sequence of reactions with different mechanism is callad hetero-domino reactions [2].

The cationic reaction involves the formation of carbocation which then reacts with nucleophile to form a new carbocation that undergoes one or more further transformations finally being trapped by a nucleophile or being stabilized by elimination of a proton. The axample of the cationic-domino reaction of biological importance is the cyclotetramerization of porphobilinogen [6], the biosynthetic precursor of protoheme, chlorophyll and vitamin B12 (Schema 2).

In anionic-domino reactions the primary step is the formation of an anion or a nucleophile. The majority of cases involve the deprotonation of CH group and formation of a carbanion which subsequently reacts with activated alkenes to produce new anionic intermediates. The large fraction of anionic processes involve either a Michael-initiated or a Michael-terminated process and generate a cyclic structure. Anionic-domino reactions were often used in the total synthesis of many natural products, e.g. corynanthe alkaloids [19], (Scheme 15).

In radical-domino reactions the formation of the primary radicals can result by reaction of halogens or from phenylthio and phenylselenyl compounds with stannanes and redox processes involving manganese compounds. In this area Snider et al. [20] have used manganese triacetate for the synthesis of tricyclic ketone (Scheme 16).

Pericyclic-domino reactions such as the Diels-Alder or electrocyclic reactions were widely used for the synthesis of complex molecules. The combination of two or more domino-Diels-Alder reactions was found to be useful procedure for the synthesis of pagodane [26], (Scheme 23). The tandem Diels-Alder reaction and 1,3-dipolar cycloaddition were used for the synthesis of pyrrolizidine [29], a structural unit of several biological active alkaloids (Scheme 26).

An example of hetero-domino reactions are the anionic-pericyclic sequences of transformation, e.g. the Knoevenagel-hetero-Diels-Alder reactions. These types of transformations can be performed as a two-components reaction of a three-components reaction (Scheme 27, 28). The tandem Knoevenagel-hetero-Diels-Alder reactions were applied by Tietze et al. [2, 32] for the synthesis of various alkaloids (Scheme 30).

Recently domino reactions have gained wide acceptance, because they increase synthetic efficiency by decreasing the number of laboratory operations required and the quantities of chemicals and solvents used.


Wiadomości Chemiczne, 1997, 51, 643.
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ANTI-JUVENILE HORMONE AGENTS

Czesław Wawrzeńczyk

Katedra Podstaw Chemii, Akademia Rolnicza we Wrocławiu, ul. Norwida 25, 50-375 Wrocław


The interference in the insect methamorphosis can be applied as a tool for insect pests population control. The development of Williams`s idea [2] of using the insect juvenile hormone analogues for this purpose afforded juvenoids 2,3 and 4 which are used in practice. The finding of agents which would be able to decrease juvenile hormone level in larvae was the next conception for obtaining a new class of insecticides. Such approach had led Bowers [1, 10] to discovery of precocene I (6) and precocene II (7), which induce precocious metamorphosis larvae in immature insects. The mode of action of precocenes involves the formation of highly reactive 3,4-epoxy derivatives in the corpora allata glands. These unstable intermediates react with surrounding proteins causing the necrotic atrophy of the corpora allata. The presentation of different types of analogues of precocenes is given in this paper. The data of biological tests carried out for some precocene analogues showed that the aromatic character of the molecule and the presence of 3,4-double bond are crucial for the appearance of the anti-juvenile activity, whereas the presence of the methoxy group is not essential for this activity [41]. The decreasing of the juvenile hormones level can be also achieved by disturbing their biosynthesis. Compounds which inhibit this biosynthesis in its earlier steps (25, 26, 27), and in the final, epoxidation step (28, 29, 30) are considered as anti-juvenile agents, too. The compounds with anti-juvenile activity for which the mode of action is unknown (33, 34, 35) [48, 59] are presented in the last paragraph of this article.


Wiadomości Chemiczne, 1997, 51, 667.
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ANALYSIS OF TRACE ELEMENTS IN BIOLOGICAL SAMPLES -SELECTED PROBLEMS

Wiesław Żyrnicki, Jolanta Borkowska-Burnecka

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


Selected problems of trace element analysis in biological samples have been presented. A brief characteristic of biological materials has been carried out. Trace elements occuring in these materials, their concentrations and some properties have been described. An attention has been focused on sampling, handling, sample treatment and preparation. Various digestion methods such as dry-ashing, fusion and wet acid procedure including microwave digestion are compared. Some problems of matrix separation and preconcentration of analyte are shown. Processes of sample contamination with examples and prevention treatment are presented. A concise overview of numerous analytical methods applied to trace element determination, their characteristics and a great number of articles and monographs referred to dealing with these problems are given. Role of reference materials is discussed. Overview of current trends in development of trace element analysis of biological materials is performed.


Wiadomości Chemiczne, 1997, 51, 681.
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SOLUBILITY PARAMETER -DETERMINATION AND APPLICATION

Adam Voelkel1, Jacek Fall2

1Instytut Technologii i Inżynierii Chemicznej, Politechnika Poznańska, pl. M.Skłodowskiej-Curie 2, 60-965 Poznań
2Instytut Technologii Nafty, ul. Łukasiewicza 1, 31-429 Kraków


A quantitative measure of the cohesive properties of a substance is the cohesive energy, and related to unit of volume is called the cohesive energy density. The square root of the cohesive energy density is called the solubility parameter and used in the description of a number of chemical systems. In the present paper the physicochemical sense and the methods of the determination of the solubility parameter and its components for polar substances are presented and discussed. Relationships existing between this physicochemical parameter and cohesive energy, entalpy of vaporisation, excess parameters and other quantities characteristic for examined substances are also briefty discussed. The possibility of the use of inverse gas chromatography for the determination of the solubility parameter and its increments for non-volatile organic compounds and natural materials is presented.


Wiadomości Chemiczne, 1997,51, 701.
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Notatki chaotyczne. XV. O JAKUBIE NATANSONIE

Ignacy Z. Siemion

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


Wiadomości Chemiczne, 1997, 51, 735.
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VI POZNAŃSKIE KONWERSATORIUM ANALITYCZNE. "NOWOCZESNE METODY PRZYGOTOWANIA PRÓBEK I OZNACZANIA ŚLADOWYCH ILOŚCI PIERWIASTKÓW"

Jan Szymanowski

-



Wiadomości Chemiczne, 1997, 51, 747.
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INTERNATIONAL SYMPOSIUM ON PHOTODYNAMIC THERAPY

Piotr Ziółkowski

-



Wiadomości Chemiczne, 1997, 51, 748.
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BIOGEOCHEMISTRY OF IRON AND MANGANESE

Zygmunt Sadowski

Instytut Inżynierii Chemicznej i Urządzeń Cieplnych Politechniki Wrocławskiej, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław


The concept of biogeochemical cycles is fundamental to proper understanding of the status of chemical elements in the nature. A biogeochemical cycle results from the integration of several biological, chemical and physical processes. All microorganisms carry out many unique reactions of geochemical significance [1].

Biogeochemistry is a multidisciplinary science. The relationships between the different sciences, which are represented by circles, can be illustrated by a diagram on Fig. 1.

Manganese is the second most abundant transition metal after iron in the earth`s crust. The cycling and movement of iron and manganese in natural systems depend on their redox chemistries. Eh-pH stability diagrams for manganese and iron at 25oC and activity of 10-5 M have been derived from thermodynamic data (Fig. 2).

Microorganisms have been implicated in transformations of both manganese and iron in soils and aquatic environments. Tab. 1 includes a list of both iron and manganese-oxidizing and -reducing microorganisms. Several different mechanisms have been proposed for the transformation of both manganese and iron from one valence state to another by microorganisms. The process of enzymatically catalyzed iron biooxidation by Thiobacillus ferrooxidans bacteria is illustrated by a scheme at Fig. 3. The mechanism of microbial formation of oxidized manganese minerals in aquatic environments has been described. Environmental conditions of pH, Ep, Mn(II) and Fe(III) concentrations and temperature have a strong influence on the form of manganese minerals [7]. Manganese minerals (todorokite, birnessite) observed in marine sediments and nodules are of microbial origin.

Marine ferromanganese nodules contain significant concentration of cobalt, some of rare earth elements, and other trace elements (Tab. 2). Bacteriological investigations of ferromanganese nodules indicate that the microbial populations are complicated [14]. Ocean-floor manganese nodules have recently attracted considerable interest as a source of such important metals as nickel, copper, cobalt, manganese and many more. A number of processes that follow pyrometallurgical and hydrometallurgical routes have been reported [14-17]. However, the hydrometallurgical processing routes are considered to be more economical. The results of leaching experiments with the use of dilute hydrochloric acid, ammonia and ammonium sulphate solutions are discussed.


Wiadomości Chemiczne, 1997, 51, 757.
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PROPERTIES OF SINGLET OXYGEN AS A STRONG ENOPHILE

Wojciech J. Kinart1, Cezary M. Kinart2, Iwona M. Kozak-Michałowska3, Ewa Śnieć3

SUP>1Katedra Chemii Organicznej, Uniwersytetu Łódzkiego, ul. Narutowicza 69, 90-136 Łódź
2Katedra Dydaktyki Chemii, Uniwersytetu Łódzkiego, ul. Pomorska 163, 90-236 Łódź
3Katedra Diagnostyki Laboratoryjnej Akademii Medycznej w Łodzi, al. Kopcińskiego 22, 90-136 Łódź


Present state of understanding of the mechanism of the hydrogen-ene reaction when the enophile is singlet oxygen is discussed. Allyl hydroperoxides are important species both from the chemical and biological points of view. They are formed when an alkene reacts with singlet oxygen [2, 7, 8] and there is good evidence from stereochemical and hydrogen isotope studies that this reaction proceeds through an intermediate ene-enophile complex, which then undergoes internal hydrogen transfer [17-19]. The reaction usually gives a single allylic isomer. In 1958, Schenck [9] showed that 5a-D6 - hydroperoxide which is formed by the singlet oxygenation of cholesterol rearranged in a non-polar solvent to the 7a-D5 - hydroperoxide. Presumably rearrangements of this type are as ubiquitous as the hydroperoxides themselves but, despite the importance of these systems, these reactions are only poorly recognised and even less understood. Only some ten examples of the rearrangement have as yet been recognised, and half of these relate to congeners of cholesterol. In general, the products of singlet oxygenation appear to rearrange to the products of triplet oxygenation. The reaction is well established to involve the intermediate radicals, but the detailed mechanism is still a matter of speculation [11-15]. It has been found that singlet oxygen and allyl hydroperoxides formed in cells of our bodies have toxic properties and they are known to cause several diseases. However, vitamins C, E and A act as natural antioxidants. Some medical aspects of the mentioned above problems are discussed. Skin injuries as bruises, overcolourings and blisters are very often caused by reactions of singlet oxygen generated in our bodies by a solar radiation [1, 29]. Singlet oxygen may be also produced by stimulated phagocytes, mainly in catalysed reactions [31-33]. Peroxidation of lipids is assumed as a main source of toxic properties of singlet oxygen metabolites [1]. Recently, researchers focused their attention on toxic properties of the oxidized LDL fraction [34-36]. Oxidation of LDL is an important factor in the pathogenesis of atherosclerosis [37-41]. However, the reactivity of singlet oxygen may be applied in treatment of herpes, jaundice of infants and psoriasis [1].


Wiadomości Chemiczne, 1997, 51, 771.
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TOPOLOGICAL INDICES AND THEIR SIGNIFICANCE IN CHROMATOGRAPHIC INVESTIGATIONS

Alina Pyka

Katedra i Zakład Chemii Ogólnej i Analitycznej Wydziału Farmaceutycznego Śląskiej Akademii Medycznej w Katowicach, 41-200 Sosnowiec, ul. Jagiellońska 4


This paper introduces some basic definitions, theorems, terms, and concepts of graph theory [1-17]. The directed graph (Fig.1), unoriented graphs (Fig. 2) and the concepts of adjacency and incidence (Fig. 3) are presented and defined [18-21]. The topological approach to the structure of organic molecules is described. Graphs, adequately labelled, may be associated with several matrices. A graph G is labelled if a certain numbering of vertices of G is introduced. Here two graph-theoretical matrices, i.e., the adjacency matrix [18-22] and the distance matrix [18, 21-24] are discussed. They are also referred to as topological matrices. The distance matrix for molecules with heteroatoms includes the diagonal elements (eq. (5)) and the off-diagonal elements (eqs. (6), (7)) which are shown in Tabs 2 and 3, respectively [21, 24]. The distances for particular paths for building the distance matrix for cis (Z) and trans (E) isomers are listed in Tab.5 [72]. Simultaneously, this paper determines a test of the achievement of partition the topological indices under discussion. Definitions of the topological indices based on the adjacency matrix (the Gutman indices [25, 26], eqs. (8), (9)); the molecular connectivity indices [27-35], Tab. 4, eqs. (10)-(13); the Platt index [44], eq. (14); the Gordon-Scantlebury index [45], eqs. (15)-(17), on the distance matrix (the Wiener index [46-49], eqs. (18), (19)); the Rouvry-Crafford index [24, 25], eq. (20); the polarity number [46, 49, 73], eq. (21); average distance sum connectivity index - Balaban [24, 74], eqs. (22)-(24); the Pyka indices [41, 72], eqs. (25)-(32); the optical topological index - Iopt [76-78], eq. (33); the stereoisomeric topological index - ISTI [77-79], eq. (34), the Hosoya index [25, 81-86], eqs. (35)-(37); the molecular topological index - MTI [87-90], eq. (38), the centric topological indices [91-93], eq. (39) and the indices based on information theory [21, 82, 92, 94-97], eqs. (41)-(47) are presented. Applications and significance of these topological indices for chemical and chromatographical investigations will be described in Part II.


Wiadomości Chemiczne, 1997, 51, 783.
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IMMUNOCHEMICAL METHODS OF TRIAZINE PESTICIDES DETERMINATION IN SOIL, WATER AND FOOD

Joanna Masłowska, Alina Owczarek, Joanna Leszczyńska

Zespół Chemii Bionieorganicznej i Analitycznej, Instytut Podstaw Chemii Żywności, Politechnika Łódzka, ul. B. Stefanowskiego 4/10, 90-924 Łódź


Chemical compounds, including pesticides, are the major contaminants in water, soil and food [1-4], bringing about the incidence of poisoning and various forms of allergy [5-9]. Due to numerous applications of herbicides in agriculture [10,11], new and better methods for their determination are constantly searched for [12].

In the present study, we deal with s-triazine derivatives (formulas I-III and Tab.1) which are slightly soluble in water, readily excreted from the organism and characterised by relatively low toxicity (Tab. 2) [13]. These herbicides are determined still by HPLC, GC and TLC methods [2, 14-16] which are very effective but require an expensive and modern equipment. Therefore, in the seventies, researches started to use the TLC method in combination with the inhibition phenomena of enzymatic processes [17-20]. These studies are continued [21,22] although in the nineties, immunoassays were used for the analysis of water and food. These methods have gained great appreciation due to the fact that they are equally sensitive as HPLC and GC methods, but they also allow one to determine a given compound selectively among many others without any sample separation and concentration.The immunochemical procedures may be defined as methods which utilise the reaction of bonding between antibody and antigen, with one of the process components being a tracer (fluorescence label, isotope or enzyme). There are qualitative methods such as the immunomorphological ones and quantitative such as the immunoassays [23], as shown in Fig.1.

In the immunoenzymatic methods, the tracer is an enzyme, while the spectrophotometric measurement of the substrate colour is a quantitative measure of the process. The most popular is the indirect method known as ELISA (enzyme linked immunosorbent assay) in which an antibody or antigen is immobilised on a solid substrate. This method has been used for several years to determine pesticides in water, soil and food [24]. The sensitivity of the ELISA method can be increased by such factors as the type of solid substrate used (magnetic particles [25-30], microplates [31], modified silicone capillaries [32-35], the use of suitable enzyme as tracer [32,36] and the use of an appropriate antibody [36-44] which is selectively linked with the given antigen.

It has been shown in papers [25-30] that the use of magnetic particles makes it possible to detect pesticides in quantities at a level of several ppb (Tab. 3) in water and soil. These are the quantities comparable with those determined by conventional methods, with the correlation coefficient of both methods being close to unity. The recovery of atrazine [31] by the ELISA method with the use of magnetic particles is the same as that in the case of using microplates (Tab. 4). The sensitivities of both methods are also comparable, although the scatter of results is lower in the first method.

The literature review and our experimental studies [24] have shown that ELISA methods are suitable for the examination of toxic components in water, soil and food, and, moreover, they can successfully replace the methods used so far. They are relatively easy in use and characterised by a high sensitivity and specificity. The relatively short time required to carry out the analysis makes it possible to use these methods to test raw materials and final products, as well as to inspect the course of technological processes.


Wiadomości Chemiczne, 1997, 51, 827.
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TOPOLOGICAL SYSTEMS FOR STRUCTURAL REPRESENTATION OF MOLECULES

Jarosław Tomczak

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


The description of the molecular topology in terms of graph theory is one of the most important aspects of chemical information handling and retrieval. There are two main groups of methods for representation of molecular constitution: linear notations and topological systems. This review presents the history and current trends of topological systems, and their application in existing data bases and computational software.

In this article we refer to topological systems as connection table or matrix representations (and their enhancements) of the topology of chemical substances as contrasted with their representation as linear sequence of symbols (called the linear notation).

The earliest reference to the use of connection-table representations of structure is that of Wheland [4,5], who has shown that acetaldehyde, for example, could be represented as well by a table of the form of Tab. 2 as by the diagrams a-c (Fig. 1). In 1951, Mooers [6] suggested that a chemical structure could conveniently be represented as a tabulation of atoms and bonds. In 1962, Meyer and Wenke [9] employed a six-column table, the columns of which had the significance shown in Tab. 3. The tabular representations of structure developed by Meyer and Wenke are substantially similar to those developed later by Gluck and his colleagues at DuPont [17,18]. About the same time as the work of Meyer and Wenke, Spialter [11] reported a "new unambiguous universal symbolism" for chemical compounds which he called the Atom Connectivity Matrix (ACM). The ACM is exactly analogous to Wheland`s matrix, except that the atom symbols are placed along the principal diagonal, rather than at the heads of columns and rows. The off-diagonal symbols of the ACM can contain bond symbols or other features of structure as desired. Other papers worth to be mentioned of that period are those of Ray and Kirsch [7] from the National Bureau of Standards; Oppler and Norton [8] from the Dow Chemical Company; Dyson, Cossum, Lynch and Morgan [15] and the most important one of Morgan [16] at Chemical Abstracts Service.

Further enhancements of representations of structures can be divided into a several groups:

(a) A compression of information stored in a connection table. A good example can be the connectivity stack proposed by Kudo and Sasaki [19], which is a sequence of elements of the connectivity matrix, obtained by application of special correspondence rules.

(b) Changing the type of data stored within graph vertices and edges. The development in this area is the most spectacular. The main achievements are the Chemical Abstracts Service registry system [20]; the Block-Cutpoint and Extended Block-Cutpoint trees by Hakayama and Fujiwara [21, 22]; Reduced Graphs described by Lynch et al. [25] for the GENSAL project; Fragment Connection Table [28] used in the Beilstein system and the Two-Level Compact Connectivity Tables of Wentang et al. [30].

(c) A replacement tables and matrices by more effective data structures, like e.g. incidence lists, what was applied for the machine storage for a Weighted Oriented Bond-Valence graphs [32].


Wiadomości Chemiczne, 1997, 51, 803.
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NONMETHANE HYDROCARBONS (NMHC) IN THE AMBIENT AIR
PART II. ANALYTICAL PROBLEMS

Magdalena Kurdziel, Elżbieta Szczepaniec-Cięciak

Wydział Chemii, Uniwersytet Jagielloński, 30-060 Kraków, ul. R. Ingardena 3


Air is a matrix very difficult to handle. In addition, nonmethane hydrocarbons (NMHC) as the pollutants are usually present at very low concentrations, so their detection and quantitation require a preconcentration step. This paper describes the enrichment methods that may be used for sampling and measuring of nonmethane hydrocarbons in ambient air. The range of sample collection methods for NMHCs in ambient air has diversified over recent years. Sampling methods now include: passivated canisters, pumped air sampling onto sorbent tubes, diffusive (passive) monitoring, on-line air sampling and analysis. Also cryogenic techniques: cryogenic focusing (CF) and cryogenic trapping (CT) have been reported. These two techniques are becoming more prevalent in today`s chromatography laboratory as very sensitive separation techniques. Gas chromatography with FID, PID or MS detection is the most often used analytical technique of determination of NMHCs in the air samples. Applications of different methods of sampling with preconcentration and the review of GC columns used for NMHCs separation have been presented. However, there are certain problems connected with each sampling procedure (air moisture, artefact formation, stability of samples, loss reactions).


Wiadomości Chemiczne, 1997, 51, 841.
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Notatki chaotyczne. XVI. O BŁĘDACH. BŁĘDY POKORY

Ignacy Z. Siemion

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



Wiadomości Chemiczne, 1997, 51, 871.
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