Synthesis and Structure of Silver and Rhodium 1,2,3-Triazol-5-ylidene Mesoionic Carbene Complexes

New mono- and bidentate 1,2,3-triazol-S-ylidene mesoionic carbene (MIC) ligands have been synthesized and reacted with silver oxide, forming cationic 1:2 and 2:2 Ag:MIC ([AgL2]Br and [Ag2L2][Ag2Br4]) complexes, respectively. These complexes have been isolated and characterized. They were further found to be potent transmetalation agents toward rhodium, resulting in the preparation of mono- and bimetallic rhodium complexes. The reaction of the 2:2 Ag:L complex with [Rh(COD)(2)]BF4 results in the first reported example of a cationic bimetallic rhodium MIC complex. This complex was fully characterized, and its X-ray structure is reported. Interestingly, this complex exhibits various secondary noncovalent interactions in the solid state of the general type C-H center dot center dot center dot X, where X = F, Cl.