- 日本結晶学会誌 (ISSN:03694585)
- vol.63, no.1, pp.2-7, 2021-02-28 (Released:2021-03-04)
Soft crystals, which are defined as flexible response systems with high structural order, respond to gentle stimuli such as vapor exposure and rubbing but maintain their ordered structures and exhibit remarkable visual changes in their shape, color, and luminescence. This article focuses on the soft crystals composed of platinum(Ⅱ) complexes bearing aromatic ligands that exhibit characteristic luminescence by assembly. When the complex units are stacked with short Pt…Pt contacts, a new emission state called 3MMLCT (i.e. metal-metal-to-ligand charge transfer) are generated on the basis of the Pt…Pt electronic interaction, and the 3MMLCT energy can change by the slight deformation of the stacking structure in response to gentle stimuli. These properties make platinum(Ⅱ) complexes soft crystals, and the precise control of the Pt…Pt interaction and other intermolecular interactions enables the precise control of photofunctions beyond the existing limitation.