Synthesis, Characterization, and Spectroscopic Studies of 2,6-Dimethylpyridyl-Linked Cu(I)-CNC Complexes: The Electronic Influence of Aryl Wingtips on Copper Centers.

Six new Cu(I) complexes containing pincer ligands of the type 2,6-bis(3-alkyl/arylimidazol-2-ylidene) methylpyridine I(R/Ar) , where R = trifluoroethyl (TFE) and R' = 4-CF, 4-NO, 4-CN, 4-H, and 4-CH, have been synthesized. These complexes, namely, [Cu(I(TFE))]PF, ; [Cu(IAr ]PF, ; [Cu(IAr )]PF, ; [Cu(IAr ]PF, ; [Cu(IAr )](PF), ; and [Cu(IAr )](PF), , were fully characterized by H, C, and HMBC NMR spectroscopy, elemental analysis, electrochemical studies, and single-crystal X-ray crystallography. The crystallographic data revealed different structures and copper nuclearities for the complexes bearing aryl wingtips with electron-withdrawing (, , and ) and electron-donating ( and ) substituents.