Co-crystal structure selection of nonlinear optical analogue polyenes

Abstract

We demonstrate co-crystallization of analogous phenolic polyene molecules that form non-isomorphic single-component crystal structures for nonlinear optical applications. The analogous polyene molecules form similar main supramolecular hydrogen-bond interactions with neighboring molecules resulting in polar linear molecular chains, but form different crystal space groups in single component crystals, which have a different orientation of these molecular chains due to subtle variations of weak intermolecular interactions. The resulting co-crystal structure is isomorphous with one of the single-component crystals. In co-crystallization with competition between two analogous crystal structures, the solubility plays an important role to select the equilibrium crystal structure of co-crystals. The phenolic polyene co-crystals retain optimal molecular ordering with large macroscopic nonlinearity of single component crystals for nonlinear optical applications.