Charge distribution in particles of transition-metal chelate complexes as the factor determining their reduction kinetics and the outer-sphere association mechanismстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:The polarographic behavior of the Co(3+), Fe(3+), Cr(3+), and vanadyl complexes with ethylenediaminetetraacetate (edta) and its analogs containing aliphatic substituents is studied. It is shown that the slopes of polarographic waves measured on a dropping mercury electrode for chelate complexes of cobalt and iron that reduce on the positively charged mercury surface are practically independent of the ligand nature, while, for chromium and vanadyl complexes, which reduce at negative charges of the electrode surface, the charge-transfer rate substantially decreases with introduction of substituents. The ratio between the reduction rate constants of [Medta] and [Mcydta] (where cydta is diaminocyclohexanetetraacetate) at a zero overpotential are similar to 1 and similar to 10 for M = Co and Cr, respectively. These results, as well as the data of spectrophotometric studies of the formation of chelate-complex/iodide(thiosulfate) anion-anion pairs are discussed with due allowance made for a nonuniform charge distribution in complex anions, which are dipoles with the positive pole near the nitrogen atoms.