Spatiotemporal Growth Anomalies in Photoisomerizable Cyanostilbene-Based Crystals Triggered by Light

Abstract

Observation of light-triggered anomalous effects on a growing crystal is important from both fundamental and technological perspectives. Our experiments focus on the aggregation of a model photoisomerizable molecule, namely, (Z)-3-(3′,5′-bis(trifluoromethyl)-[1,1′-biphenyl]-4-yl)-2-(4-bromophenyl) acrylonitrile (1), under tight-focused laser light. Phenomenally, by shining a light of specific wavelength at the growing crystal facet-solution interface, crystal growth can be precisely paused, resumed, and reversed. By focusing laser light at just half of the growing facet, many subcrystals (split growth) can be grown exclusively in the light-illuminated area. The presented laser-triggered rare effects can be extended to control the aggregation processes artificially in biological molecules and materials.