Synthesis and crystal structures of two mixed-ligand Cu(II) complexes of tripyridyldiamine

Two novel Cu(II) complexes, [Cu(H(2)tpda)(acac)](ClO4)(0.5)Cl0.5 center dot H2O, [Cu(H(2)tpda)(NO3)] ClO4 (2) (H(2)tpda = tripyridyldiamine) have been synthesized, and characterized by X-ray analyses, elemental analyses, IR, UV and ESR spectra. Single crystal X-ray diffraction revealed that the Cu atom in complex 1 is coordinated to three N atoms from H(2)tpda and two oxygen atoms from acac with an approximately trigonal bipyramidal geometry. The molecules are assembled through intermolecular hydrogen bonds and pi-pi stacking, affording a two dimensional network. In complex 2, the Cu atom is coordinated with three N atoms from H(2)tpda and two oxygen atoms from NO3- in addition to a weak coordination with one oxygen from ClO4-, resulting in an irregular octahedral environment, and the molecules are also connected by intermolecular hydrogen bonding and pi-pi stacking, affording a one dimensional structure.