Octahedral cobalt(III) complexes of the chloropentammine type. XXVII. Effects of Methyl Substituents on reactivities of the cis‐chloro‐n‐propylaminebis(ethylenediamine)‐cobalt(III) cation

Abstract

AbstractSalts of one isomeric form of the chloro‐n‐butylamine‐, chloro‐iso‐butyl‐amine‐ and chloro‐sec‐butylamine‐bis(ethylenediamine)cobalt(III) cations have been prepared and characterised to have a cis‐configuration (IR and VIS spectroscopy). Rate constants for their spontaneous aquation, mercury(II)‐induced aquation and base hydrolysis have been determined and the activation parameters calculated. The results are compared with data obtained for the n‐propylamine complex with a view to investigate the effects of methyl (α, β, γ) substituents on reactivities.The rate‐determining dissociation of the outgoing group (Cl− or HgCl+) takes place via either a square‐pyramidal or a trigonal‐bipyramidal intermediate, depending on whether the activation entropy is negative or positive.