Recent Advances of Single-Crystal to Single-Crystal Transformation for Discrete Coordination Compounds

In this short review we highlight the diversity of single-crystal to single-crystal transformations that has been discovered in the last few years in the field of coordination cluster chemistry. In particular, we focus on phase transformations which involve a chemical change such as bond formation, oxidation-reduction, electron-transfer, and ligand exchange, which will, for example, cause spin-crossover or switch non-linear optical activity. We first deal with crystals without guests followed by those losing guest or exchange ligands during the transformations and discuss how guests are involved before focusing on the rare occurrence of chemical reactions that take place on molecular components within crystalline solids without destroying the long-range crystalline state. Finally, a perspective following these advances made in the field is developed.