Synthesis, structures and photoluminescence properties of silver complexes of cyclic (alkyl)(amino) carbenes

Silver complexes of cyclic (alkyl)(amino) carbenes (CAACs), (L-R)(n)AgX (n = 1, X = Cl, Br, I; n = 2, X = OTf; R = Me2, Et-2, or adamantyl) are accessible in high yields by reacting free carbenes with silver salts. The smaller carbene ligand L-Me2 leads to the formation of a mixture of neutral (L-Me2) AgCl and cationic [(L-Me2)(2)Ag](+) products. The transmetallation of (L-Ad) AgCl with copper and gold halides gives the corresponding copper and gold compounds (L-Ad) MCl (M = Cu and Au) in a clean and quantitative reaction. Whereas (L-Me2) AgCl is monomeric in the solid state, (L-Et2) AgCl crystallizes as a Cl-bridged dimer. None of the compounds show metal-metal interactions. The complexes show blue photoluminescence, which consists of a fluorescence component with a lifetime of several nanoseconds, as well as a long-lived emission in the microsecond regime. (C) 2017 Elsevier B. V. All rights reserved.