THE STRUCTURE AND NONLINEAR-OPTICAL PROPERTIES OF ROPYLAMIDE-4-(4-HEXYLOXYPHENYLETHYNYL)-NITROBENZEN

We have synthesized the tolane derivative opylamide-4-(4-hexyloxypheny lethynyl)-nitrobenzene 1 and examined its second-order nonlinear prope rties and crystal structure. Compound 1 crystallizes in the space grou p C1c1 with a = 27.667(6), b = 4.910(2), c = 20.856(3) Angstrom, beta = 128.36(3)degrees and Z = 4, and shows a high second-order nonlinear optical efficiency. It has an intermolecular hydrogen bond between C = O and N-H in the amide group. This hydrogen bond plays an important r ole in forming a non-centrosymmerric structure appropriate for nonline ar optical materials. (C) 1998 Elsevier Science B.V. All rights reserv ed.