Das Redoxverhalten des Hexakismethylisonitrilmangan(I)-Ions in Propylencarbonat

摘要

Employing voltammetric and polarographic methods the hexakismethylisonitrilemanganese(I) Mn(L)6+ ion was found to undergo two oxidation steps to hexakismethylisonitrilemanganese(II) and hexakismethylisonitrilemanganese(III) as well as a reduction to the metal. Using bisbiphenylchromium(I) iodide BBCr(I)I throughout this study as a reference system cyclic voltammetry yielded a value of 2.29 V for the oxydation Mn(L)62+/Mn(L)63+and 1.11 V for the oxydation Mn(L)6+/Mn(L)62+vs.BBCr(I)I. The half wave potential on the dropping mercury electrode for the oxidation Mn(L)6+/Mn(L)62+aggreed within the limits of experimental error with the value obtained by cyclic voltammetry, theE1/2for the reduction was found to be −1.87 V vs.BBCr(I)I. Large scale electrolysis, coulometry and the rotating platinum electrode were used to learn about the nature of the reaction and the reaction products. 0.1Msolutions of tetraethylammonium perchlorate tetrabutylammonium perchlorate and tetraethylammonium nitrate served as supporting electrolytes. The standard rate constant for the reaction Mn(L)6+/Mn(L)2+was 1.1·10−2cm·sec−1and for the reaction Mn(L)62+/Mn(L)63+4,7·10−3cm·sec−1. The UV-spectra of Mn(L)6+and Mn(L)62+were