Achieving a series of solid-state [2 + 2] cycloaddition reactions involving 1,2-bis(2-pyridyl)ethylene within halogen-bonded co-crystals

The solid-state [2 + 2] cycloaddition reaction of trans-1,2-bis(2-pyridyl)ethylene through both co-crystallization and mechanical grinding is reported. The photoreaction is achieved by using iodoperchlorobenzene as a molecular template. The co-crystal...