Structural and photophysical features of triphenylene–gold(I) phosphane complexes

Abstract

Two series of mono- or dinuclear gold(I) complexes incorporating an ethynyltriphenylene chromophore and various mono- and diphosphanes have been synthesized and characterized to explore the interplay between the ligand structure, aurophilic interactions, and photophysical properties. The complexes display dual emission behaviour, with fluorescence dominating under air-equilibrated conditions and phosphorescence emerging under oxygen-free environments. Dinuclear compounds bearing diphosphane linkers show enhanced phosphorescence, attributed to shorter Au(I)-Au(I) distances that facilitate intersystem crossing (ISC). Upon immobilization in PMMA matrices, all selected compounds exhibit efficient room-temperature phosphorescence even in the presence of oxygen, with emission quantum yields up to 33% and lifetimes extending to nearly one millisecond. These findings highlight the potential of structural design and matrix confinement to engineer metal-based luminophores for applications in time-gated imaging, security inks, and light-emitting devices.