Linker-dependent chromogenic control of the emission of polymethylene-vaulted trans-bis(salicylaldiminato)platinum(II) complexes

The emission wavelengths of polymethylene-vaulted trans-bis(salicylaldiminato)platinum(II) complexes 1a-f (n=8-13) in a 2-MeTHF glass state at 77 K clearly vary with the length of the linker, such that a very regular hypsochromic shift from yellow to green is observed upon transitioning from octamethylene (1a, n=8) to tridecamethylene (1f, n=13) linkages. This structure-dependent chromism is explained based on DFT and TD-DFT calculations comparing the T1-S0 gaps in optimized 1a, 1c (n=10) and 1e (n=12) structures.