Polymorph driven diversification of photosalient responses in a zinc(II) coordination complex.

A novel crystallographic form of a Zn(II) coordination complex [Zn(4-ohbz) 2 (4-nvp) 2 ] (1-Form-III) (H4-ohbz = 4-hydroxybenzoic acid and 4-nvp = ( E )-4-(1-naphthylvinyl)pyridine), undergoes a solid-state photochemical [2+2] cycloaddition reaction accompanied by a moderate photosalient effect, whereby single-crystals show cracking and splitting. This UV-induced cycloaddition accompanies a single-crystal to single-crystal transformation, allowing for continuous monitoring of the unit cell parameters. The new polymorph represents an intermediate form of the two previously reported crystallographic forms of [Zn(4-ohbz) 2 (4-nvp) 2 ], and provides novel insight into moderating the magnitude of photosalient responses across polymorphic materials.