Synthesis, coordination to Au(i) and photophysical properties of a novel polyfluorinated benzothiazolephosphine ligand

Abstract

The reaction between Ph₂PH and C₆F₅CNS leads to the formation of the polyfluorinated benzothiazolephosphine ligand Ph₂P(CNS)(C₆F₄) 1. The mechanism of the reaction involves the addition of the phosphine to the isothiocyanate and subsequent intramolecular nucleophilic aromatic substitution. This new ligand reacts with gold(I) substrates producing complexes [AuCl{Ph₂P(CNS)(C₆F₄)}] 2 and [Au(C₆F₅){Ph₂P(CNS)(C₆F₄)}] 3. Both the ligand 1 and complexes 2 and 3 display phosphorescence with emissions arising from n(P) → π*(heterocyclic ring) excited state for 1 and π → π*(heterocyclic ring) excited state for 2 and 3. DFT and TD-DFT calculations agree with these results.