Cationic nitrile-functionalized Ag(I)- and Hg(II)-N-heterocyclic carbene complexes of CCC, CNC, and NCN pincer-type carbene ligands: Synthesis, crystal structures, and characterization

Three nitrile-functionalized (benz)imid- zaolium derivatives with CCC, CNC, and NCN coordination pockets have been synthesized and isolated as the bromide salts and are converted into their hexafluorophosphate counterparts (57) by ligand metathesis. N-heterocyclic carbene Ag(I)- and Hg(II)-complexes (810 and 1113) are readily formed in good to excellent yields from ligand precursors 57 and Ag2O and Hg(OAc)2, respectively. All reported compounds have been characterized by various spectral and analytical techniques, such as FTIR, 1H, and 13C NMR spectroscopy and X-ray diffraction studies. Solid-state structures of carbene precursors 5, 7, and an Ag(I)carbene complex 10 have been determined crystallographically. Single crystal X-ray crystallography of complex 10 reveals the chelation of carbene carbons to metal center in almost a linear manner. (C) 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:486497, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21041