HYDROLYTICALLY-SENSITIVE HEXAIMINO AND HYDROLYTICALLY-INERT OCTAAMINO-CRYPTAND HOSTS FOR DICOPPER

The hexa-Schiff-base cryptand N[(CH2)(2)N=CH(C6H4-m)CH=N(CH2)(2)]N-3 L(1) has been found to encapsulate a pair of Ag-1 or Cu-1 cations without hydrolytic attack on the imine bonds; a problem which is evident when the [Cu-2(II)(OH)](3+) assembly is incorporated. The structure of the dicopper complex of a singly ring-opened ligand, derived from L(1), has been determined. The octaamine cryptand L(2) (= L(1) + 12H) more easily accommodates a [Cu-2(mu-X)](3+) assembly where X = imidazolate, N-3(-) or OH-. Collinear disposition of the bridge with the N-br-N-br axis is confirmed in the first case by an X-ray crystallographic structure determination of the imidazolate-bridged cryptate, and inferred for the second case by spectroscopic and magnetic data, while, for the third case, magnetic susceptibility data indicate severe bending of the Cu-O(H)-Cu assembly.