Reactions of palladium dichloride with 4-(trimethylammonio)benzenethiolate and phosphine ligands

Abstract

Reactions of PdCl2·2H2O with 2equiv. of 4-(trimethylammonio)benzenethiolate (Tab) (prepared in situ from a mixture of TabHPF6 and Et3N in MeOH) and seven phosphine ligands: PPh3, 1,1-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,4-bis(diphenylphosphino)butane (dppb), N,N,N′,N′-tetra(diphenylphosphanylmethyl)ethylene diamine (dppeda), and 1,4-N,N,N′,N′-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda), afforded a family of mononuclear and dinuclear Pd(II)/Tab/phosphine complexes, [Pd2(PPh3)2(Tab)2(μ-Tab)2](PF6)4 (1), [Pd2(dppm)2(Tab)2(μ-Tab)](PF6)4 (2), [Pd2(dppb)(Tab)2(μ-Tab)2]Cl4 (3), [PdL(Tab)2](PF6)2 (4: L=dppe; 5: L=dppp) and {[PdL(Tab)2]2}Cl4 (6: L=dppeda; 7: L=dpppda). These compounds were characterized by elemental analysis, IR spectra, UV–Vis spectra, 1H and 31P{1H} NMR, electrospray ionization (ESI) mass spectra and single-crystal X-ray diffraction. In the structure of 1–7, each Pd(II) adopt an approximate square planar coordination geometry. The results provide an interesting insight into the chemistry of palladium(II)/thiolate/phosphine complexes.