Unexpected and facile equilibration of six-co-ordinate bis(solvento)-(R,S,S,R)(1,4,8,11-tetramethyl-1,4,8,11-tetra-azacyclotetradecane)nickel(II) ions with the five-co-ordinate mono(solvento)-(R,S,R,S)-complexes in some co-ordinating solvents

Abstract

The belief that the complexes of 1,4,8,11-teramethyl-1,4,8,11-tetra-azacyclotetradecane are thermodynamically stable in the trans-III or R,S,S,R configuration (A) is shown to be incorrect; there is substantial conversion into the trans-I or R,S,R,S geometry (B) at a relatively slow rate in some non-aqueous solvents such as dimethyl sulphoxide, but surprisingly rapidly in the presence of a strongly co-ordinating amine such as n-propylamine.