TY - JOUR
T1 - Silver and Palladium Complexes Containing Ditopic N-Heterocyclic Carbene–Thione Ligands
AU - Slivarichova, Miriam
AU - Reading, Eamonn
AU - Haddow, Mairi F.
AU - Othman, Hafiizah
AU - Owen, Gareth
PY - 2012/8/31
Y1 - 2012/8/31
N2 - The mixed donor N-heterocyclic carbene (NHC)/thione ligand precursors [1-(3-R-2H-imidazol-1-yl-2-thione)methyl-3-R-2H-imidazol-2-ium]X, [HCSR]X (R = methyl, benzyl; X = Br, I), have been utilized to prepare a range of silver and palladium complexes. The coordination of CSR to silver(I) salts has been explored, providing dimeric complexes of the type [AgX(CSR)]2 (where R = methyl, benzyl; X = Br, I). Structural characterization of [AgX(CSBn)]2 revealed a bidentate coordination mode for the mixed donor ligand and dinuclear structures where the silver centers are bridged by two bromido centers. Palladium complexes bearing one or two CSR ligands have additionally been prepared either directly, utilizing [Pd(OAc)2] as precursor, or via transmetalation strategies. The dicationic complexes [Pd(CSR)2][X]2 and neutral complexes [PdX2(CSR)] (where R = methyl, benzyl; X = Br, I, PF6) have been synthesized and fully characterized. The CSR ligand in the aforementioned complexes does not undergo transformation of the NHC unit to a urea function, which had been found to occur in the previously reported copper complexes. Palladium complexes containing both NHC/thione and bis-phosphine ligands were also prepared. Complexes of the type [Pd(CSMe)(L2)][X]2 and [PdX(CSMe)(L2)][X] (where L2 = dppe, dppp; X = Br, OAc, I, PF6) were obtained. The presence of the bis-phosphine appears to destabilize the coordination of the NHC/thione ligand and as a consequence leads to its elimination from the complex.
AB - The mixed donor N-heterocyclic carbene (NHC)/thione ligand precursors [1-(3-R-2H-imidazol-1-yl-2-thione)methyl-3-R-2H-imidazol-2-ium]X, [HCSR]X (R = methyl, benzyl; X = Br, I), have been utilized to prepare a range of silver and palladium complexes. The coordination of CSR to silver(I) salts has been explored, providing dimeric complexes of the type [AgX(CSR)]2 (where R = methyl, benzyl; X = Br, I). Structural characterization of [AgX(CSBn)]2 revealed a bidentate coordination mode for the mixed donor ligand and dinuclear structures where the silver centers are bridged by two bromido centers. Palladium complexes bearing one or two CSR ligands have additionally been prepared either directly, utilizing [Pd(OAc)2] as precursor, or via transmetalation strategies. The dicationic complexes [Pd(CSR)2][X]2 and neutral complexes [PdX2(CSR)] (where R = methyl, benzyl; X = Br, I, PF6) have been synthesized and fully characterized. The CSR ligand in the aforementioned complexes does not undergo transformation of the NHC unit to a urea function, which had been found to occur in the previously reported copper complexes. Palladium complexes containing both NHC/thione and bis-phosphine ligands were also prepared. Complexes of the type [Pd(CSMe)(L2)][X]2 and [PdX(CSMe)(L2)][X] (where L2 = dppe, dppp; X = Br, OAc, I, PF6) were obtained. The presence of the bis-phosphine appears to destabilize the coordination of the NHC/thione ligand and as a consequence leads to its elimination from the complex.
U2 - 10.1021/om300615e
DO - 10.1021/om300615e
M3 - Article
VL - 31
SP - 6595
EP - 6607
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 18
ER -