Regioselective [2 + 2] cycloaddition reaction within a pair of polymorphic co-crystals based upon halogen bonding interactions
The realization of a pair of photoreactive polymorphic co-crystals that are held together by the combination of I⋯N halogen bonding interactions and C-H⋯Cl contacts is reported. The reactant molecule within these co-crystals is based upon an unsymmetrical olefin, namely 4-stilbazole, that results in a regioselective solid-state [2 + 2] cycloaddition reaction in both polymorphic forms. Each solid undergoes a quantitative photoreaction which yields exclusively the head-to-tail photoproduct.
Bosch, Eric, Samantha J. Kruse, Eric W. Reinheimer, Nigam P. Rath, and Ryan H. Groeneman. "Regioselective [2+ 2] cycloaddition reaction within a pair of polymorphic co-crystals based upon halogen bonding interactions." CrystEngComm 21, no. 43 (2019): 6671-6675.