Some cyclic tetra-amines and their metal-ion complexes. Part VIII. Cobalt(III) complexes of 3,3-dimethyl-1,5,8,11-tetra-azacyclotridecane

Abstract

The preparation of the cyclic tetra-secondary amine 3,3-dimethyl-1,5,8,11-tetra-azacyclotridecane from the previously reported nickel(II) complex is described. Cobalt(III) complexes of the amine were prepared with the amine in planar (bcde-octahedral) and folded (abcd-octahedral) co-ordination. Derivatives of the complex cobalt cation in three configurations arising from restricted inversion at the four chiral co-ordinated secondary amino-groups were prepared. The relative stabilities of the possible configurations in planar and folded coordination are discussed, and assignments of configuration of the observed forms are made, based on chemical and physical (particularly ¹H n.m.r. spectral) properties.