Photomechanical effect in Zn(II) and Cd(II) 1D coordination polymers: photosalient to non-salient behaviour.

A Zn(II) based one-dimensional (1D) coordination polymer (CP), [Zn( cis -1,4-chdc)(4-nvp)] (1) { cis -1,4-H 2 chdc = cis -1,4-cyclohexanedicarboxylic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine}, undergoes a solid-state photochemical [2+2] cycloaddition reaction, accompanied by mechanical motion, wherein crystals show swelling, jumping, splitting and bursting upon UV irradiation, whereas the analogous Cd(II) CP [Cd( cis -1,4-chdc)(4-nvp)] (2) does not show any such response under UV light, although it undergoes [2+2] photodimerization. The present study can certainly provide the fundamental understanding for designing smart photoactuating materials.