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

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) -->pi*(heterocyclic ring) excited state for 1 and pi-->pi*(heterocyclic ring) excited state for 2 and 3. DFT and TD-DFT calculations agree with these results.