Some cyclic tetra-amines and their metal-ion complexes. Part VII. Nickel(II) complexes of some tetra-aza-cyclotridecane derivatives

Abstract

Nickel(II) complexes of 3,3-dimethyl- and 2,4,4-trimethyl-1,5,8,11-tetra-azacyclotrideca-1-ene and 3,3-dimethyl-1,5,8,11-tetra-azacyclotridecane are described. Singlet ground-state square-planar complexes are formed with poorly co-ordinating anions such as tetrachlorozincate. Triplet ground-state ‘octahedral’ complexes are formed with the co-ordinating anions oxalate, acetate, acetylacetonate (all as chelates) with thiocyanate and azide, and with diaminoethane. The three cations exist as configurational isomers, arising from restricted inversion at the asymmetric co-ordinated secondary amine centres.