Polarographic study of the reactions of cis- and trans-dicyanochromium(III) complexes with Hg2+ ions

Potentiometry and polarography were used to study the reactions of some cis - and trans-dicyanochromium(III) complexes with Hg(ClO4)(2). Potentiometric investigation revealed the different stoichiometry of the reactions of cis and trans complexes. The results of polarographic study were consistent wi th the potentiometric investigations of the reaction stoichiometry and enab led to propose the course of the reaction and the structure of the reaction products. It was found that the configuration of the cyano groups cis or t rans of the chromium(III) complex plays a crucial role in the structure of oligonuclear compounds. It is supposed that cis-dicyano complexes may assoc iate either through single or double bridges. The latter circumstance is no t incurred with trans-dicyano complexes obviously because of the unfavourab le cyano groups position.