Spectroscopic and Phosphorescent Modulation in Triphosphine-Supported PtAg2 Heterotrinuclear Alkynyl Complexes

A series of highly phosphorescent PtAg2 heterotrinuclear alkynyl complexes with bis­(diphenylphosphinomethyl)­phenylphosphine (dpmp) were prepared and characterized structurally. The solution phosphorescence with various emitting colors is systematically modulated by modifying substituents as well as π-conjugated systems in aromatic acetylides. The crystals, powders, or films exhibit reversible stimuli-responsive phosphorescence changes upon exposure to vapor of MeCN, pyridine, DMF, etc., resulting from perturbation of d8-d10 metallophilic interaction in the excited states as a consequence of the formation/disruption of Ag–solvent bonds. Both experimental and time-dependent density functional theory (TD-DFT) studies demonstrate that d8-d10 metallophilic interaction exerts a crucial role on phosphorescent characteristics due to the PtAg2 cluster-based 3[d → p] state. This study affords a paradigm for phosphorescence modulation in d8–d10 heteronuclear complexes.