Controlled Linker Dependence of Solution- and Solid-State Emission of Vaulted trans-Bis(salicylaldiminato)platinum(II) Complexes with Amino Functionalities

The synthesis, structures, and emission properties of vaulted trans‐bis(salicylaldiminato)platinum(II) complexes 1 with diethylamino functionalities are described and compared with the non‐substituted analogues. The amino substitution provides an improvement of the linker dependence both for the color change of the trans‐bis(salicylaldiminato)platinum(II) platform in the glass state and for the acid‐induced emission enhancement in the solution state. The linker dependence of the crystalline‐state emission intensity changes with the amino functionality, which leads to intense emission of the vaulted crystals with low structural dependence. Single‐crystal X‐ray diffraction studies and DFT calculations revealed that the unique photophysical properties arising from the amino functionality are attributable to enhanced planarity and self‐constraint of the coordination platform, which is due to their strong contribution to d–π conjugation and intermolecular hydrogen bonding. Amino substitution provides an improvement of the linker dependence of both the color change of the trans‐bis(salicylaldiminato) PtII platform in the glass state and the acid‐induced emission enhancement in the solution state. The linker dependence of the solid‐state emission intensity changes with the amino functionality and leads to intense emission of the vaulted crystals.