title: Syntheses and structures of dinuclear gold(I) dithiophosphonate complexes and the reaction of the dithiophosphonate complexes with phosphines: diverse coordination types.
abstract: The dinuclear gold(I) dithiophosphonate complex, [Au(2)(dtp)(2)] (1), where dtp = [S(2)P(R)(OR')](-) with R = p-C(6)H(4)OCH(3); R'= c-C(5)H(9), has been synthesized and its reaction studied with the phosphine ligands PPh(3) and Ph(2)P(CH(2))(n)PPh(2) (n = 1-4). Compound 1 contains two gold atoms homobridged by the anionic dithiophosphonate ligand, forming an eight-membered ring complex in a chair form. After the reaction of 1 with diphosphine ligands, the dinuclear open-ring complexes Au(2)(dppm)(dtp)(2) (2), Au(2)(dppe)(dtp)(2) (3), Au(2)(dppp)(dtp)(2) (4), Au(2)(dppb)(dtp)(2) (5) were formed (dppm = diphenylphosphinomethane; dppe = diphenylphosphinoethane; dppp = diphenylphosphinopropane; dppb = diphenylphosphinobutane). The reaction with dppm is stoichiometry-dependent. Thus, when 1 reacts with 2 equiv of dppm, the ionic complex [Au(2)(dppm)(2)(dtp)]dtp forms. This dtp counterion was exchanged with tetrafluoroborate to yield [Au(2)(dppm)(2)(dtp)]BF(4), the crystallization of which afforded two interconvertible isomers, 6-yellow and 7-white. Reaction of 1 with PPh(3) affords the tetracoordinate mononuclear complex [Au(dtp)(PPh(3))(2)] (8). The molecular structures of 1-8 were confirmed by X-ray crystallography and show multiple coordination modes and geometries. The crystal structures of 1 and its reaction products with dppm (2, 6, 7) show short intramolecular Au.Au aurophilic bonding interactions of 2.95-3.10 A while no intermolecular interactions were discernible. However, reaction products of 1 with longer-chain Ph(2)P(CH(2))(n)PPh(2) ligands, n = 2-4, exhibit structures that lack both intra- and intermolecular Au.Au interactions.
authors.affiliation: Department of Chemistry and Laboratory for Molecular Structure and Bonding, Texas A&M University, P.O. Box 30012 College Station, Texas 77842-3012, USA.
authors.forename: Angelo
authors.initials: A
authors.lastname: Maspero
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Kani
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Mohamed
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Omary
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Staples
authors.forename: John P
authors.initials: JP
authors.lastname: Fackler
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D009946:Organothiophosphorus Compounds / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D009946:Organothiophosphorus Compounds; D010720:Phosphines