Complexes of nickel(II) with some 1,5,8,12-tetra-azacyclotetradecane derivatives; two isomeric cyclic tetraimines and a cyclic tri-iminemonoamine

Abstract

Nickel(II) complexes of the isomeric cyclic tetraimines, 2,4,4,9,11,11-hexamethyl-1,5,8,12-tetra-azacyclotetradeca-1,5,8,12-tetraene and 2,4,4,9,9,11-hexamethyl-1,5,8,12-tetra-azacyclotetradeca-1,5,7,11-tetraene, have been prepared by the nitric acid oxidation of the appropriate (1,8- and 1,11-respectively) diene nickel(II) complexes. Both cations are reduced by aqueous borohydride or hydrogen with platinum catalyst to reform the diene complexes. The nickel(II) complex of the 2,4,4,9,9,11-hexamethyl isomer is reduced by hypophosphorous acid to yield the cyclic tri-iminemonoamine 2,4,4,9,9,11-hexamethyl-1,5,8,12-tetra-azacyclotetradeca-1,5,11-triene, as the nickel-(II) complex. Singlet ground-state square-planar derivatives, e.g. perchlorate salts, and triplet ground-state octahedrally co-ordinated derivatives, e.g. dithiocyanato-derivatives, are described. I.r., electronic, and n.m.r. spectra, and magnetic susceptibilities are reported.