Copper(I) complexes containing 1,1′-bis(diphenylphosphino) ferrocene (dppf) as a chelate ligand. X-ray crystal structures of [Cu2(μ-Cl)2(κ2-P,P-dppf)2] and [Cu(CNtBu)2(κ2-P,P-dppf)][BF4]

Copper(I) complexes [Cu(CNR)2(κ2-P,P-dppf)][BF4] (R=tBu (1), 2,6-Me2C6H3 (2), Cy (3), Bz (4)) containing the chelating dppf ligand (dppf=1,1′-bis(diphenylphosphino)ferrocene) have been prepared by reaction of the complex [Cu2(μ-Cl)2(κ2-P,P-dppf)2] with the corresponding isocyanide CNR (molar ratio 1:1). Alternatively, complexes 1–4 can also be obtained by the reaction of the acetonitrile complexes [Cu(MeCN)2(κ2-P,P-dppf)][BF4] with 2.5 equivalents of CNR in refluxing dichloromethane. The crystal structures of [Cu2(μ-Cl)2(κ2-P,P-dppf)2] and [Cu(CNtBu)2(κ2-P,P-dppf)][BF4], determined by X-ray diffraction, are also reported.