Organic Polarography Research Articles

Professor Petr Zuman: Life and Legacy

This lecture will address Prof. Zuman’s legacy and influence through the experiences of one of his scientific sons and one of his scientific grandsons. Petr was born and raised in the city of Prague during the rather tumultuous events of World War II. Early academic achievements after the war included a PhD in Physical Chemistry from Charles University in 1950, under future Nobel laureate Prof. J. Heyrovsky, who invited him to join the new Polarographic Institute in Prague in 1950. Shortly afterwards, Petr was appointed head of the Organic Electrochemistry Division of the Polarographic Institute and launched his research career in organic electrochemistry. He was both originator and major innovator in this area, which he focused on for the rest of his life. In 1967, he was awarded Dr. Science, Czech Acad. Sci. Also in this year, his influential monograph P. Zuman, Substituent Effects in Organic Polarography, was published.In 1966 Petr took up to a guest professorship at University of Birmingham in the UK. In 1970, he moved to Clarkson University as Professor of Chemistry. In 1991, he retired as Distinguished Emeritus Research Professor, but kept active in research into his 90’s. Over his long career, Petr published nearly 500 papers and dozens of books, and mentored 100s of undergrads, grad students, and postdocs and other researchers. He was the ultimate pioneer in development of the field of Organic Electrochemistry, which is now gaining renewed popularity. This talk will also illustrate Petr’s influence on the research efforts of the authors.

Guest Editorial, Petr Zuman 90th Birthday Issue

Guest Editorial, Petr Zuman 90th Birthday Issue

J. Heyrovský, Japan, and Organic Polarography

Polarography is an electroanalytical technique based on recording current-voltage curves using a dropping mercury as the working electrode. It can be used for investigations of both reductions and oxidations of inorganic and organic species. Before WWII the developments of this technique linked Prague (in the then Czechoslovakia) with Kyoto (in Japan, where reductions of organic compounds were first observed). After WWII wide use of this technique has developed, so that in the 1950s and 1960 it became the fifth most frequently used analytical technique. More recently the analytical applications were limited to those of heterogeneous solutions and analyses of some drugs. Its applications in physical organic chemistry involve studies of structure-reactivity relationships and applications to investigations of equilibria and kinetics of rapidly or slowly established processes.

Electrochemistry of chromium(0)–aminocarbene complexes: The use of intramolecular interaction LFER for characterization of the oxidation and reduction centre of the complex

Two series of chromium(0)–(aryl)aminocarbene complexes substituted on the ligand phenyl ring were prepared and electrochemically investigated: pentacarbonyl(( N,N-dimethylamino)(phenyl)carbene(chromium(0) ( Ia– e) and chelated tetracarbonyl((η 2- N-allyl- N-allylamino)(phenyl)carbene(chromium(0) ( IIa, c– e). For comparison, a tungsten analogue of IIc ( III) and a chromium chelate bearing a methyl substituent instead of the phenyl group IV were taken into the study. The intramolecular interactions of p-substituents on the ligand phenyl ring with the reduction and oxidation centres of the molecule of complex (followed electrochemically using LFER [P. Zuman, Substituent Effects in Organic Polarography, Plenum Press, New York, 1967]) enabled to localize the corresponding electron transfer. The influence of the type of coordination, the substituent on the ligand phenyl ring and the central metal atom on oxidation and reduction potentials is discussed.

Applied Polarography and Voltammetry of Organic Compounds in Pratical Day-To-Day Analysis Part II

In organic chemistry, polarography and voltammetry are most frequently applied for the solution of (1) practical, mainly analytical, problems. To show the scope and possibilities of these techniques in the analysis of dyes, agricultrual products, plastics, and pharmaceutical materials we shall briefly, and in a nonexhaustive way, discuss some practical examples. Polarography can also be used for (2) the solution of electrochemical problems, and (3) to provide useful information on fundamental problems of organic chemistry such as determination of equilibrium constants, and rate constants for fast (t,1/2 <0.5 sec) and slow (T,1/2 < 10 sec) reactions, detection of intermediates, etc. The reproducibility of polarographic measurements (about 3%) allows obtaining of kinetic data with a precision comparable to that of most other methods used in reactions kinetics. Because applications of the types (2) and (3) have been covered in sufficient detail elsewhere,136, 195, 345, 346 we shall restrict our discussion to...

Organic polarography

Organic polarography

Organic polarography

Organic polarography

Organic polarography

Organic polarography

New books - Organic polarography

New books - Organic polarography

Organic polarography.

Organic polarography.

Organic polarography

Organic polarography

Organic Polarography

Organic Polarography

Recent trends in organic polarography

Abstract

Organic Polarography

Organic Polarography

Slowly established acid-base equilibrium in organic polarography: Tautomeric changes between 3-thianaphthenone and 3-hydroxythianaphthene

In solutions of 3-thianaphthenone, the cathodic wave of a two-electronreduction decreases and the anodic wave of a two-electron oxidation increases with increasing pH, in accordance with a theoretical acid-base dissociation curve. The limiting currents are diffusion-controlled in the pH-range studied and the polarographically-determined p K-value is in good agreement with the p K-value determined spectrophotometrically. The electrode process is, hence, accompanied by a sluggishly established equilibrium between the reducible keto-form and the oxidizable anion. The slow dissociation of the acid is attributed to the C-acid structure of the keto-form.

Organic Polarography

Organic Polarography

The theory of catalytic hydrogen waves in organic polarography

The theory of catalytic hydrogen waves in organic polarography

Organic Polarography, Structure and Linear Free Energy Relationships

It was like in an old fairy tale: When Professors J. Heyrovský and M. Shikata parted, each brought a problem with him home : There were mainly inorganic problems studied in Czechoslovakia whereas much stress has been laid on organic polarography in Japan. This division even when not without notable exceptions remained until early forties. It is thus not surprising that it was from the pen of M. Shikata and I. Tachi from which the first papers on correlations between the structure and polarography of organic substances appeared. The famous Shikata-Tachi rule was a guide of organic polarographers for almost two decades, basing on the qualitative knowledge of theoretical organic chemistry of these days.Since then organic polarography broadened considerably its scope and also the understanding of the electrode processes got more profound. Japanese scientists joint in this venture and helped to our understanding of the polarographic behaviour of organic substances. Professor I. Tachi and his coworkers contributed substantially in this respect. When the quantitative treatment of structural effects was developed, polarography applied such methods to the treatment of half-wave potentials. Again Japanese chemists took part in that development (cff the references later in the text part). Thus it is a great priviledge to contribute to the volume devoted to Professor I. Tachi in the field he himself fostered. In addition to rate and equilibrium constants, for which these relationships were originally devised, several physico-chemical quantities were correlated using Hammett and Taft equation and similar free energy relationships. Whereas for most other physico-chemical quantities, like the wave-length of the maximum of a selected band in UV-spectra or like quadrupole coupling constants, these correlations are at present purely empirical, for polarographic half-wave potentials the explanation for such correlations between electrochemical data and equilibrium and kinetic data (expressed through the values of the substituent c constants) can be suggested.

Organic Polarography

Organic Polarography

Organic Polarography

Organic Polarography