Two Cu2 and Zn2 metallamacrocycles featuring a novel extended pi-conjugated carbazole bridge

Two neutral dinuclear metallamacrocycles, Cu2(hbca)2].2CHCl3.2H2O (1) and Zn2(hbca)2].7H2O (2), have been assembled from reactions of the new rigid carbazole-based ligand H2hbca N,N'-bis(2-hydroxobenzylidene)-9H-carbazole-3,6-diamine] with copper(II) or zinc(II) acetate. The extended aromatic ligand spacer is responsible for intermetallic antiferromagnetic exchange, which is rationalized using the spin-polarization formalism with the help of density functional theory calculations.