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

Abstract

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