title: Geminally diaurated aryls bridged by semirigid phosphine pillars: syntheses and electronic structure.
abstract: Geminally diaurated μ2 -aryl complexes have been prepared where gold(I) centers were bridged by the semirigid diphosphine ligands bis(2-diphenylphosphinophenyl)ether (DPEphos) and 4,6-bis(diphenylphosphanyl)dibenzo[b,d]furan (DBFphos). Diaurated complexes were synthesized in ligand redistribution reactions of the corresponding di-gold dichlorides with di-gold diaryls (six of them new) and silver(I) salts. Diaurated complexes were isolated as salts of the minimally coordinating anions SbF6 (-) and ReO4 (-). Efforts to prepare salts of the tetraarylborate [B(3,5-(CF3)2 C6 H3)4](-) led to transmetalation from boron, with crystallization of the fluorinated aryl complex. The new complexes were characterized by multinuclear NMR, absorption and emission spectroscopies, 77 K emission lifetimes, and by combustion analysis; three are crystallographically characterized. Structures of geminally diaurated aryl ligands are compared to those of mono-aurated analogues. Both crystal structures and density-functional theory calculations indicate slight but observable disruptions of aryl ligand aromaticity by geminal di-gold binding. An intermolecular aurophilic interaction in one structurally authenticated complex was examined computationally.
authors.affiliation: Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (USA).
authors.forename: Amberle R
authors.initials: AR
authors.lastname: Browne
authors.forename: Nihal
authors.initials: N
authors.lastname: Deligonul
authors.forename: Bryce L
authors.initials: BL
authors.lastname: Anderson
authors.forename: Arnold L
authors.initials: AL
authors.lastname: Rheingold
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Gray
keywords: aromaticity; aurophilicity; density functional calculations; gold; phosphine ligands