Bonding μ1,3- (trans) vs μ1,2- (cis) in squarato-bridging dinuclear copper(II) complexes derived from pyridyl amine ligands

A novel series of trans- and cis-dinuclear squarato-bridged copper(II) complexes: [Cu2(dpya)4(μ1,3-C4O4)](ClO4)2·MeOH (1), [Cu2(bdmpzpy)2(μ1,3-C4O4)(H2O)2](ClO4)2·5H2O (2) and [Cu2(pmea)2(μ1,2-C4O4)](ClO4)2·1.5H2O (3) where dpya = di-2-pyridylamine, bdmpzpy = 2,6-bis[(2,5-dimethyl-1H-pyrazolyl)methyl]pyridine and pmea = bis(2-pyridylmethyl)-2-(2-pyridylethyl)amine were structurally and magnetically characterized. Complexes reveal weak antiferromagnetic interaction between the Cu2+ centers.