Syntheses, crystal structures, and magnetism of one-dimensional complexes generated from copper(II) and carbamyldicyanomethanide bridging ligand

Two one-dimensional chain complexes, {[Cu(cda)(2)H2O].H2O}(n) (1) and {[Cu(cda)(H2O)(2)].ClO4).3H(2)O}(n) (2) (cda = carbamyldicyanomethanide anion) have been synthesized and their crystal structures determined by X-ray crystallography. The copper(II) ions in 1 are bridged by two mu(1,5)-cda bridging ligands, whereas in 2 the copper(II) ions are connected by a single mu(1,5)-cda ligand. Complex 1 is red while 2 is green. Variable-temperature magnetic susceptibility data indicate that there is a very weak antiferromagnetic interaction between the bridged copper(II) ions in both 1 and 2.