Synthesis, structure, and electrochemical reduction of 2-(arylazo)pyridine complexes of rhodium(III)

Abstract

The synthesis of new halogenorhodium(III) 2-(arylazo)pyridine(L) complexes of the type [RhX₂L₂]ClO₄·H₂O (X = Cl, Br, or I; aryl = Ph, C₆H₄Me-m or -p) are described. From their spectral data it has been shown that the complexes are cis, trans, cis in the following sequence: Cl,Cl; N(pyridine), N(pyridine); and N(azo), N(azo). They are electroactive and display several cyclic voltammetric reductive responses on the negative side of a saturated calomel electrode. E.s.r. studies of the electrolysed solutions indicate that the electrons are added successively to the ligand centre.