A novel binuclear copper(II) complex: Bis[1,10-phenanthroline-N,N '-maleato-O,O '-copper(II)] dimethanol tetrahydrate

A novel binuclear Cu(II) complex, [Cu-2(mal)(2)(phen)(2)] . 4H(2)O . 2MeOH (phen = 1,10-phenanthroline, mal = maleate dianion), has been synthesized a nd characterized by elemental analysis, IR spectroscopy, solid-state ESR an alysis and X-ray single crystal study. The complex consists of [Cu(mal)(phe n)] subunits with two water and one methanol solvate molecules. The subunit s show a distorted planar arrangement, existing in centrosymmetrically rela ted pairs in the crystal packing. They have a distorted four-coordinate squ are-planar arrangement of N and O atoms about the central Cu atom; pairs of these [Cu(mal)(phen)] subunits form dimers by interaction of the fifth pos ition on each Cu center with an O atom of a maleate ligand of the associate d subunit with a Cu-Cu distance of 3.3425(9) Angstrom. The coordination aro und each Cu atom is best described as distorted square-pyramidal. The latti ce water and methanol molecules are also confirmed by the TG study and IR s pectra. The X-band solid-state ESR spectrum at room temperature exhibits an anisotropic feature with g(parallel to) = 2.24, g(perpendicular to) = 2.06 .