Crystal engineering of molecular NLO materials

Efficient second‐order nonlinear optical materials are produced by optimizing the orientation of non‐centro‐symmetrically packed donor–acceptor chromophores. Practical approaches for inducing the favored alignment, for example incorporation of chirality into the chromophore (as shown in the Figure) and H‐bond‐induced self‐assembly of ionic or molecular aggregates, are briefly reviewed. magnified image