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