Synthesis, C-N cleavage and photoluminescence of gold(III) isocyanide complexes

Abstract
The synthesis and crystal structure of the gold(III) isocyanide complexes [(CˆNˆC)AuCNtBu]+X- (1a, X = (C6F5)3BOAcF; 1b, X = PF6) are reported [(CˆNˆC) = 2,6-bis(4-ButC6H3)2pyridine; OAcF = trifluoroacetate]. Compound 1a slowly decomposes under C–N bond cleavage of the tBuNC ligand, to give (CˆNˆC)AuCNB(C6F5)3 and tBuOAcF, whereas [(CˆNˆC)AuCNtBu]PF6 decomposes mainly to [(CˆNˆC)AuCN. On UV irradiation the complexes show photoluminescence, with (CˆNˆC)AuCN showing the most intense emission.

Graphical abstract
The gold(III) isocyanide pincer complex [(CˆNˆC)Au-CNtBu][AcFOB(C6F5)3] decomposes to cyanide products via C–N bond cleavage, to give complexes with enhanced photoemission.