Polymeric nickel(II) and copper(II) complexes with btc2- ions as bridging ligands (btc2-=1,2,4,5-benzenetetracarboxylic acid dianion)

Two new complexes of composition {[Ni(L)(btc(2-))].2H(2)O}(n) (1) {L = 1,4,8,11-tetraazacyclotetradecane} and {[Cu(L)(btc(2-))].H2O}(2) (2) were obtained by reacting [Ni(L)].2ClO4 or [Cu(L)].2ClO(4) and btc, and their structures were determined by analytical, spectroscopic, and X-ray diffraction methods. The blue complex I and violet complex 2 consist of ID polymeric chains with nickel(II) or copper(II) macrocycles and bridging btc(2-) ligands, respectively. In I the COO- groups on the 1,4-positions of the btc(2-) ligand are coordinated to the central nickel(II) atom, but in 2 the COOH groups on the 1,5-positions of the btc(2-) ligand are involved in interacting with the central copper(II) atom through an unusual carbonyl coordination. (C) 2003 Elsevier Science B.V. All rights reserved.