Syntheses and Crystal Structures of Two New Nickel(II) Complexes with Salicylidene-2-ethanolamine

Two new Schiff base complexes of nickle(II) [C18H20NiN2O4]center dot 1.5H(2)O (1) and [C18H2ON2NiO4]center dot H2O (2) were synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray crystal structure analysis. Both 1 and 2 crystallize in the orthorhombic system. Crystal 1: space group Pbcn with a = 12.8591(19), b = 14.779(2), c = 19.749(3) angstrom, V = 3753.3(10) angstrom(3), C18H23N2NiO5.5, M-r = 414.07, Z = 8, D-c = 1.445 g/cm(3), mu = 1.067 mm(-1), F(000) = 1712, S = 1.037, the final R = 0.0741 and wR = 0.2101 for 4353 observed reflections (I > 2 sigma(I)) and R = 0.1157 and wR = 0.2380 for all data. Crystal 2: space group P2(1) with a = 9.4673(17), b = 11.559(2), c = 16.347(3) angstrom, V = 1788.9(6) angstrom(3), C18H22N2NiO5, M-r = 405.07, Z= 4, D-c = 1.497 g/cm(3), mu = 1.116 mm(-1), F(000) = 840, S = 1.085, the final R = 0.0330 and wR = 0.0869 for 3151 observed reflections (I > 2 sigma(I)) and R = 0.0362 and wR = 0.0887 for all data. Each Ni atom of 1 and 2 is six-coordinated with two nitrogen atoms and four oxygen atoms from two salicylidene-2-ethanolamine ligands yielding a distorted octahedral geometry. Dimer structure is observed in the packing diagram of 1. The thermal stability of complex 2 is also studied.