title: Synthesis, characterization, and luminescence studies of discrete polynuclear gold(I) sulfido and selenido complexes with intramolecular aurophilic contacts.
abstract: The synthesis, characterization, and photophysical and photochemical properties of a family of high-nuclearity gold(I) chalcogenides, specifically, the gold(I) sulfido and selenido complexes containing different bridging diphosphine ligands with nuclearities of ten ([Au10{μ-Ph2PN(R)PPh2}4(μ3-E)4](2+)) and six ([Au6{μ-Ph2PN(R)PPh2}3(μ3-E)2](2+)), are reported. The X-ray crystal structures of the complex cations of Au10 and Au6 are found to be propeller-like structures and distorted cubane structures, respectively, with the presence of short intramolecular gold···gold distances. The complexes show intense green and/or orange phosphorescence upon photoexcitation in the solid state and in solution at ambient and low temperature. The emission properties are found to be strongly dependent on the nuclearities and the chalcogenido ligands, but are rather insensitive to the substituents on the bis(diphenylphosphino)amines. The emissions are tentatively assigned to originate from the excited states derived from the phosphine-centered intraligand (IL) transition or metal-centered (ds/dp) mixed with ligand-to-metal-metal charge transfer (LMMCT) (E→Au) transition. The photochemical properties of the complexes were also studied by transient absorption spectroscopy.
authors.affiliation: Institute of Molecular Functional Materials [Areas of Excellence Scheme, University Grants Committee (Hong Kong)], and Department of Chemistry, The University of Hong Kong , Pokfulam Road, Hong Kong, PR China.
authors.forename: Eddie Chung-Chin
authors.initials: EC
authors.lastname: Cheng
authors.forename: Wing-Yin
authors.initials: WY
authors.lastname: Lo
authors.forename: Terence Kwok-Ming
authors.initials: TK
authors.lastname: Lee
authors.forename: Nianyong
authors.initials: N
authors.lastname: Zhu
authors.forename: Vivian Wing-Wah
authors.initials: VW
authors.lastname: Yam