Synthesis, crystal structure and properties of a novel di-mu(2)-aqua bridged binuclear manganese(III) Schiff base complex [Mn(vanen)(H2O)(2)](2)(ClO4)(2) center dot 2H(2)O

The preparation and isolation of the binuclear manganese(III) complex, [Mn( vanen)(H2O)(2)](2)(ClO4)(2) . 2H(2)O was accomplished by air oxidation of a solution containing H(2)vanen**, Et3N, and Mn(ClO4)(2) . 6H(2)O in absolut e EtOH. The crystal structure of complex was determined by X-ray crystallog raphy, and consists of two molecules bridged by two water molecules through hydrogen bonding. The manganese atom is six-coordinate and presents a dist orted octahedral coordination sphere, which consists of the two imine N ato ms and two phenolic O atoms of vanen(2-) ligand in the equatorial plane, wi th Mn-N bond distances of 1.975 and 1.987 Angstrom, and Mn-O distances of 1 .867 and 1.876 Angstrom, respectively. The non-bonding interatomic Mn ... M n distance is 4.79 Angstrom. In the axial direction, the elongated Mn-O(H2O ) bond distances of 2.255 and 2.381 Angstrom, respectively, are due to Jahn -Teller distortion at the d(4) metal center. The presence of lattice and co ordinate water molecules were also confirmed by the t.g. study and the i.r. spectra. Upon irradiation using visible light in water in the presence of p-benzoquinone, the complex demonstrates its ability to split water.