Copper(II) and zinc(II) complexes with macrocyclic ligand: Structure variation via counteranion and co-ligand

Seven new metal complexes [Zn2(L)Br2](ClO4)2 (1), [Cu2(L)Br2]Br2·2H2O (2), [Cu2(L)(H2O)2](ClO4)4·1.03H2O (3), [Cu6(L)3(H2O)2Br2(N3)](ClO4)9·2H2O (4), [Cu4(L)2Br4(im)2]Br2·15H2O (5), [Cu2(L)(bpy)2](ClO4)4·2bpy·2H2O (6) and [Cu2(L)(tp)]Br2·6H2O (7) (N3- = azide anion; im− = imdazolate anion; bpy = 4,4′-bipyridine; tp2− = terephthalate dianion) have been synthesized by reactions of macrocyclic ligand 3,6,9,12,20,23,26,29-octaazatricyclo[29.3.1.114,18]hexatriaconta-1(34),14,16,18(36),31(35),32-hexaene (L) and metal salts with different counteranion and/or co-ligand. Interestingly, there are [Zn2L]4+/[Cu2L]4+ dinuclear units with different conformations of chair-type in 1, 2, 6 and 7, boat-type in 5 and mixed chair- and boat-types in 3, 4. The complexes 1, 2, 3 and 6 have dinuclear molecular structure, and 4 has dimer of [Cu2L]4+ linked by azide and 5 displays tetranuclear molecular rectangle bridged by imidazolate groups, while 7 has 1D chain structure in which the [Cu2L]4+ units linked by terephthalate anions. The results revealed that the structure, coordination ability and coordination mode of anions and/or co-ligands have great impact on the structure of the complexes.