Binuclear nickel(II) and copper(II) complexes of amide-containing two-armed and macrocyclic ligands

Abstract

Two new acyclic, potentially binucleating amide-containing ligands.H3L1 andH3L2, have been synthesised from the reaction of 4-methylphenol-2,6-diacyl chloride with an excess of 1,2-diaminobenzene or of 1,2-diamino-4,5-dimethylbenzene, respectively. Dicopper(II) complexes, [Cu2(L1)(X)] where X = CH3COO− or OH−, ahve been made fromH3L1 but the analogous nickel complexes could not be prepared and no complexes with either copper or nickel could be prepared fromH3L2. Interestingly, Schiff-base macrocyclic complexes derived from reactions ofH3L1 andH3L2 with 2,6-diformyl-4-methylphenol, 4-t-butyl-2,6-diformylphenol, or S-(2,6-diformyl-4-methyl-phenyl)-dimethylthiocarbamate, were successfully templated using these same two metal ions and resulted in the isolation of nine dimetallic complexes. A variety of structural modifications were made to the macrocycles via the choice dialdehyde precursor, including changing a phenolate bridge for a thiophenolate one, in an attempt to increase the solubility of the products.