title: Bromide ion binding by a dinuclear gold(I) N-heterocyclic carbene complex: a spectrofluorescence and X-ray absorption spectroscopic study.
abstract: Fluorescence and X-ray absorption spectroscopy were used to investigate the anion binding properties of a luminescent, dinuclear Au(I) N-heterocyclic carbene (NHC) complex ([1](2+)) with a short Au(I)···Au(I) contact. The addition of Br(-) ions to a DMSO solution of [1](PF(6))(2) caused a red-shift in the fluorescence emission band from 396 nm to 496 nm. Similarly, the addition of Br(-) ions to [1](PF(6))(2) caused a decrease in the energy of the Au L(3)-edge in the X-ray absorption spectrum, consistent with the formation of an association complex between the cation [1](2+) and Br(-) ions. Solution-based structural studies of the association complex were carried out using extended X-ray absorption fine structure (EXAFS) modelling of the Au(I)···Au(I) core of the cation. These studies indicate that the association complex results from Au(I)···Br(-) interactions, with the Br(-) ions occupying two partially occupied sites at ~2.9 and 3.9 Å from the Au(I) atoms.
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast Campus, QLD 4222, Australia.
authors.forename: Louise E
authors.initials: LE
authors.lastname: Wedlock
authors.forename: Jade B
authors.initials: JB
authors.lastname: Aitken
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Berners-Price
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Barnard
mesh_terms: D001965:Bromides / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D056928:X-Ray Absorption Spectroscopy
chemical_list: D001965:Bromides; D056831:Coordination Complexes; D007477:Ions; C030011:carbene; D006046:Gold; D008697:Methane