Strong hydrogen bonds as a design element for developing new non-linear optical crystals: Co-crystals of merocyanine dyes and phenol derivatives

In this work we show that with strong hydrogen bonds, including a 'very strong' hydrogen bond and/or strong hydrogen-bonding networks, highly non-linear optically active chromophores, merocyanine dyes and phenol derivatives, are assembled as salt or semi-salt crystals, leading to improvement in crystallinity and interesting non-linear optical properties. Our approach is discussed in connection with four co-crystal structures.