Crystal morphology and their lattice contraction control for the topochemical reaction of bis(phenylethenyl)-dicyanopyrazines

Abstract

Topochemical photoreaction of bis(phenylethenyl)-dicyanopyrazines (1) was conducted in solution, in the vapor deposited thin film, and in the single crystals. Compound 1 showed the crystal morphology to give the yellow and orange colored crystals. The difference in crystal structures of yellow and orange crystals was confirmed with X-ray crystal analysis which revealed that the orange one was contracted in the crystallographic c-axis by 0.11 angstrom than that of the yellow one at the same temperature. The physical property and photoreactivity of two crystals were explained with the topochemical control and lattice contraction. (c) 2006 Elsevier Ltd. All rights reserved.