New hydrogen-bonded molecular crystals with nonlinear second-order opticalproperties

Fifteen new hydrogen-bonded crystals exhibiting nonlinear optical propertie s were obtained. For the morpholinium dihydrogenphosphate crystal, the stru cture was determined by the X-ray diffraction methods. This crystal belongs to the P2(1) space group of the monoclinic system. The lattice parameters are as follows: a = 8.345(2), b = 6.156(1), c = 9.109(2) Angstrom; beta = 1 16.64(3)degrees. The crystal is built up of the layers parallel to the (001 ) crystallographic planes. The layer consists of the dihydrogenphosphate ch ains running parallel to the [010] direction. The morpholinium cation parti cipates in two hydrogen bonds with the O(4) oxygen atoms of dihydrogenphosp hate anions belonging to two neighbour chains shifted by the a distance. In such a way, the chains of dihydrogenphosphates are joined by the morpholin ium cations into the layer parallel to the (001) crystallographic plane. Ad ditionally, the powder IR and Raman spectra are presented for this crystal. (C) 2000 Elsevier Science B.V. All rights reserved.