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Redoks aktywne receptory kationów i anionów

Zięba K., Taraszewska J.

Wiadomości Chemiczne

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2008

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[Z] 62, 3-4

237-267

EN

The electrochemical recognition of cationic, anionic and neutral guests is a fast expanding research area on the interface of electrochemistry and supramolecular chemistry. Its aim is the development of highly sensitive and selective receptors [2, 3]. The redox-active receptors usually consist of two units: the guest binding site and the redox-active unit. After complexation of a guest at the binding site, the changes of the electrochemical properties of redox-active center give information about the complexation. The idea of redox-active receptors is presented in Scheme 1. The present review is devoted to different types of redox-active receptors for cationic and anionic guests. Receptors able to recognize cations are presented according to the mechanism of a communication between redox-active and binding units. These mechanisms are: through bonds communication, through space communication, direct coordination of a cation to redox-active center and the conformational change of redox-center mechanism. In the next chapter are discussed the redox-active receptors for anions according to the type of the redox-active center. In complexation of anionic guests the major role plays the possibility of the creation of hydrogen bonds between anion and receptor. The most extensively studied redox center was ferrocen. Nowadays, in the construction of redox-active receptors more often complexes of metal cations are used [53, 54].

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Życie i dzieło prof. Wiktora Kemuli (w stulecie urodzin)

Grabowski Z.R., Taraszewska J.

Kwartalnik Historii Nauki i Techniki

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2002

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R. 47, nr 1

9--32

EN

In his life - in this part of Europe where the wars, foreign occupations, changes of frontiers and of political systems intervened again and again - these external events heavily influenced the scientific and pedagogical activities of the eminent scholar, prof. Wiktor Kemula (6.III.1902-17.X. 1985). PhD student and later successor of prof. Stanisław Tołłoczko in Lwow (starting his research mostly in photochemistry of alkanes), W. Kemula became inspired for most of his life by his post-doc work with prof. Jaroslav Heyrovsky in Prague. The polarography and analytical chemistry were henceforth the main field of his interest and research. His fast academic career (at the age of 37 he became full professor of Inorganic Chemistry at the University of Warsaw) was interrupted for 6 years by the outbreak of the World War II. Most of his pre-war co-workers were killed, the Soviet frontiers were shifted westward, leaving Lwow out of the Polish borders, and the Warsaw University Chemistry building was in ruins. Several years of activity of prof. Kemula were sacrified to restoring the normal teaching and research. In 1946 he led 250 Polish students to work in the Copenhagen laboratories for the Danish vacation time. For many years he was suspected and harassed by the communist regime. He became the vice-rector of the University of Warsaw only in the period of a political thaw in 1956. To the most known achievements of Wiktor Kemula and his group belong the new instrumental methods, chromato-polarography and the cyclic voltammetry with a hanging mercury drop electrode In 1968 he was fired by the authorities from the University, deprived any contact with teaching and with the students; his name was for years prohibited by the censorship to be published by the media. He headed afterwards only his pure-research laboratory in the Institute of Physical Chemistry of the Polish Academy of Sciences. The University begged his pardon and delivered him the doctor h.c. degree only at the period of th zfirst „Solidarity”, in 1981. In spite of all that, Wiktor Kemula gained a great public and international recognition for his research and activities, becoming, i.a., the honorary President of the Polish Chemical Society, President of the Warsaw Learned Society, and the President of the Analytical Division of IUPAC. Fully active till the end, Wiktor Kemula suddently died - entering the church, where the choir was just starting to sing the Mozart’s Requiem. He left over 400 papers, and from among of his PhD students over 30 became university professors. They continue the research in the fields inspired by their onetime teacher.

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Solvent extraction of inorganic and organic cations by octakis-O-diphenoxyphosphoryl-tetramethylcalix[4]resorcinarene

Taraszewska J., Koźbiał M.

Chemia Analityczna

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2002

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Vol. 47, No. 3

409-418

EN

Extraction of alkali metal, alkaline-earth metal Mg(II), Ca(II) cations and ammonium picra-tes as well as of Eu(IIl) and La(IlI) nitrates by complexation with octakis-O-diphenoxyphos-phoryl-tetramethylcalix[4] resorcinarene was studied by a liquid-liquid extraction from aqueous phase into chloroform. Extraction percentages (E%), stoichiometry and overall extraction constants (Kex) were determined. E% increased in the order lanthanum, europium >alka-line earth cations >ammonium cations>alkali cations. The stoichiometry of the complexes was 1:1. Kex increased with the increase of cation charge.

PL

Zbadano ekstrakcję z fazy wodnej pikrynianów metali alkalicznych, ziem alkalicznych Mg(II), Ca(II) i alkiloammoniowych oraz azotanów Eu(III) i La(lII) w wyniku komplekso-wania roztworem oktakis- difenoksyfosforylo-tetrametylokaliks[4]rezorcynarenu w chloroformie. Wyznaczono procenty ekstrakcj i (E%), stechiometrie, i stale ekstrakcj i (Kex). E% wzrastał w kolejności, lantan, europ >kationy metali ziem alkalicznych >kationy alkiloamo-niowe >kationy metali alkalicznych. Stechiometria kompleksów była1: 1. Kex wzrastała ze wzrostem ładunku kationu

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Stability and ESR Spectra of Ni(III) Tetraazamacrocyclic Complexes in Nitrate and Chloride Solutions

Taraszewska J., Sadło J., Michalik J., Korybut-Daszkiewicz B.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 6

813-822

EN

Complexes [NiIII(cyclam)Cl2]Cl (10, NiIII(cyclam)(NO3)2]lO4 (2) and [NiIII(2-methyl-cyclam)(NO3)2]ClO4 (3) were isolated and the stability of Ni(III) was studied by UV-VIS spectrophotometry as a function of NaCl and NaNO3 concentration. In complexes 2 and 3 the decay of Ni(III) followed the first order kinetics in aqueous and nitrate solutions up to 1 ol/dm3. In complex 1 the first order kinetics was observed only in aqueous and saturated NaCl solutions. With increase in NaNO3 concentration the stability of Ni(III) in complexes 2 and 3 increased however, in complex 3 it was lower than in complex 2. Stability of Ni(III) in complex 1 increased also with increasing NaCl concentration but it diminished starting from 2 mol/dm3 NaCl. The forms of complexes depending on the salt concentration were characterized by the ESR technique.