title: Synthesis and structures of cyclic gold complexes containing diphosphine ligands and luminescent properties of the high nuclearity species.
abstract: A mixture of cyclic gold(I) complexes [Au(2)(μ-cis-dppen)(2)]X(2) (X = OTf 1, PF(6)3) and [Au(cis-dppen)(2)]X (X = OTf 2, PF(6)4) is obtained from the reaction of [Au(tht)(2)]X (tht = tetrahydrothiophene) with one equivalent of cis-dppen [dppen = 1,2-bis(diphenylphosphino)ethylene]. The analogous reaction with trans-dppen or dppa [dppa = bis(diphenylphosphino)acetylene] affords the cyclic trinuclear [Au(3)(μ-trans-dppen)(3)]X(3) (X = OTf 11, PF(6)12) and tetranuclear [Au(4)(μ-dppa)(4)]X(4) (X = OTf 13, PF(6)14, ClO(4)15) gold complexes, respectively. Recrystallization of 15 from CH(2)Cl(2)/MeOH yielded a crystal of the octanuclear gold cluster [Au(8)Cl(2)(μ-dppa)(4)](ClO(4))(2)16. Attempts to prepare dicationic binuclear gold(II) species from the reaction of a mixture of 3 and 4 with halogens gave a mixture of products, the components of which confirmed to be acyclic binuclear gold(I) [Au(2)X(2)(cis-dppen)] (X = I 5, Br 7) and cyclic mononuclear gold(III) [AuX(2)(cis-dppen)]PF(6) (X = I 6, Br 8) complexes. Complexes 11-14 reveal weak emission in butyronitrile glass at 77 K, but they are non-emissive at room temperature. Ab initio modelling was performed to determine the charge state of the gold atoms involved. Extensive structural comparisons were made to experimental data to benchmark these calculations and rationalize the conformations.
authors.affiliation: Advanced Materials & Industrial Chemistry, School of Applied Sciences, RMIT University, GPO Box 2476V, Melbourne, Victoria 3001, Australia. Suresh.bhargava@rmit.edu.au
authors.forename: Suresh
authors.initials: S
authors.lastname: Bhargava
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kitadai
authors.forename: Takahashi
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authors.lastname: Masashi
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Drumm
authors.forename: Salvy P
authors.initials: SP
authors.lastname: Russo
authors.forename: Vivian Wing-Wah
authors.initials: VW
authors.lastname: Yam
authors.forename: Terence Kwok-Ming
authors.initials: TK
authors.lastname: Lee
authors.forename: Jörg
authors.initials: J
authors.lastname: Wagler
authors.forename: Nedaossadat
authors.initials: N
authors.lastname: Mirzadeh