PREPARATION, PROPERTIES AND CRYSTAL-STRUCTURES OF NEW NICKEL(II) COMPLEXES OF 1,2-ASYMMETRICALLY SUBSTITUTED DITHIOLENES FOR 3RD-ORDER NONLINEAR-OPTICAL APPLICATIONS

Three new nickel(II) complexes of 1-alkyl-2-phenyl asymmetrically subs tituted dithiolenes [Ni(SCR1=CR2S)2] (R1 = Ph; R2 = Bu(n), cyclopentyl methyl or 4-pentylcyclohexyl) have been prepared and their electrochem ical properties and near-IR spectra studied. The crystal structures of the complexes in which R2 = Bu(n) or cyclopentylmethyl have been dete rmined. The presence of bulky substituents adjacent to the ring has no affect upon the electrochemical or near-infrared properties. Third-or der non-linear optical coefficients were measured by degenerate four-w ave mixing.