Cleavage of [Pd 2 (PP) 2 ( μ -Cl) 2 ][BArF 24 ] 2 (PP = Bis(phosphino)ferrocene, BArF 24 = Tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) with Monodentate Phosphines

The addition of Na[BArF ] (BArF = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) to [Pd(PP)Cl ] (PP = 1,1'-bis(phosphino)ferrocene ligands) compounds results in the loss of a chloride ligand and the formation of the dimeric species [Pd (PP) ( -Cl) ][BArF ] . In most cases, the addition of a monodentate phosphine, PR , to these dimeric species leads to cleaving of the dimer and formation of [Pd(PP)(PR )Cl][BArF ]. While these reactions are readily observed via a significant color change, the P{ H} NMR spectra offer more significant support, as the singlet for the dimer is replaced with three doublets of doublets. The reaction seems to take place for a wide range of PR ligands, although there do appear to be steric limitations to the reaction. The compounds were thoroughly characterized by NMR, and X-ray crystal structures of several of the compounds were obtained. In addition, the ferrocenyl backbone of the 1,1'-bis(phosphino)ferrocene ligands provides an opportunity to examine the oxidative electrochemistry of these compounds. In general, the potential at which oxidations of these compounds occurs shows a dependence on the phosphine substituents.