Three new dinuclear copper(II) complexes, [Cu2(L1)2(µ-ox)](ClO4)22(CH3CN), [Cu2(L2)2(µ-ox)](ClO4)2H2O and [Cu2(L3)2(µ-ox)](ClO4)2 where ox = oxalato; L＝N,N-dimethyl,N'-benzylethane-1,2-diamine, L1, N,N-diethyl,N'-benzylethane-1,2-diamine, L2, N,N-diisoprophyl,N'-benzylethane-1,2-diamine, L3, were prepared and characterized by elemental analyses, spectral (IR, UV-Vis) data and molar conductance measurements. The crystal structures of [Cu2(L1)2(µ-ox)](ClO4)22(CH3CN) and [Cu2(L3)2(µ-ox)](ClO4)2 have been determined by single-crystal X-ray analysis. Their solvatochromic behaviors were investigated in various organic solvents, showing positive solvatochromism. The effect of steric hindrance around the copper ion imposed by N-alkyl groups of the diamine chelates on the solvatochromism property of the complexes was discussed. Their solvatochromism were also studied with different solvent parameter models using stepwise multiple linear regression (SMLR) method.
