N-Methyl-substituted ethane-1,2-diamine complexes of dichlororhodium(III)

Abstract

The synthesis and spectroscopic properties of some complexes of the type trans-[RhCl₂(N–N′)₂]⁺(N–N′=N-methyl-,NN′-dimethyl-,NN-dimethyl,NNN′-trimethyl-, and NNN′N′-tetramethyl-ethane-1,2-diamine, men, sdmen, udmen, trimen, and tetmen, respectively) are described and the previously reported route to trans-[RhCl₂(udmen)₂]⁺ is shown to give a cis-isomer. The chemical and polarographic-reduction behavious of the complexes is reported together with a kinetic study of chloride–bromide exchange in trans-[RhCl₂(N–N′)₂]⁺(N–N′= men, udmen, trimen, or tetmen). The activation parameters for the reaction of trans-[RhCl₂(tetmen)₂]⁺ with bromide ion have been determined and are discussed in relation to literature data for the analogous reactions of trans-[RhCl₂(en)₂]⁺and trans-[RhCl₂(NH₃)₄]⁺.