Crystal structures and magnetic interactions in nickel(II) dibridged complexes formed by both phenolate oxygen-azide, or methanlate groups

Tridentate Schiff base ligands L-1 and L-2, derived from the condensation of 2-hydroxy-3-methoxybenzaldehyde (L) with 2-aminoethanol or 2-aminobutan-1-ol, react with nickel chloride, azide, or thiocyanate to give rise to two dinuclear complexes of formulas [Ni-2(L)-(L-1)(2)N-3]center dot H2O (1), [Ni-2(L-2)(3)(mu(1,1)-N-3)]center dot 2H(2)O (2), and one tretranuclear complex [Ni-2(L-2)(2)(NCS)](2)(C2H5OH)(2) (3), where L-1 = HOCH2CH(C2H5)NCHC6H3(O-)(OCH3) and L-2 = HO(CH2)(2)NCHC6H3(O-)(OCH3). We have characterized these complexes by analytical, crystal structures, and variable temperature magnetic susceptibility measurements. The magnetic properties of the complexes are studied by magnetic susceptibility (chi(M)) vs. temperature measurements. The chi T-M vs. T plots reveal that compounds 1, 2 and 3 are ferromagnetically coupled.