Second harmonic generation from the single crystals of N-substituted 4-cyanoanilines

Six N-substituted derivatives of 4-cyanoaniline (pCA) were synthesized and their physical and optical properties were examined in the search for second-order nonlinear optical materials with enough crystal dimensions together with blue-light transparency. Among the derivatives examined, N-diphenyimethyl-pCA and N-2-naphthylmethyl-pCA afforded single crystals that lack a center of symmetry. Although the second harmonic (SII) activities of these derivatives were not enough for the practical purposes. their cut-off wavelengths were shorter than 330 nm and showed sufficient blue-light transparency. Quantitative prediction of the SH activity was also attempted (C) 2000 Elsevier Science B.V. All rights reserved.