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

Tridentate Schiff base ligands L1 and L2, 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 [Ni2(L)(L1)2N3]·H2O (1), [Ni2(L2)3(μ1,1-N3)]·2H2O (2), and one tretranuclear complex [Ni2(L2)2(NCS)]2(C2H5OH)2 (3), where L1 = HOCH2CH(C2H5)NCHC6H3(O−)(OCH3) and L2 = HO(CH2)2NCHC6H3(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 (χM) vs. temperature measurements. The χM T vs. T plots reveal that compounds 1, 2 and 3 are ferromagnetically coupled. Crystal of two dimers and one tetranuclear nickel (II) complexes were determined. Two dimers are azide/phenolate double bridged, and the tetranuclear is Ni4O4 cubane complex. And magnetic properties show that these compounds are ferromagnetically coupled.