title: Molecular design of luminescence ion probes for various cations based on weak gold(I)...gold(I) interactions in dinuclear gold(I) complexes.
abstract: A series of luminescent dinuclear gold(I) complexes with different crown ether pendants, [Au(2)(PwedgeP)(S-B15C5)(2)] [S-B15C5 = 4'-mercaptobenzo-15-crown-5, P(wedge)P = bis(dicyclohexylphosphino)methane (dcpm) (1), bis(diphenylphosphino)methane (dppm) (2)] and [Au(2)(P(wedge)P)(S-B18C6)(2)] [S-B18C6 = 4'-mercaptobenzo-18-crown-6, P(wedge)P = dcpm (3), dppm (4)], and their related crown-free complexes, [Au(2)(P(wedge)P)(SC(6)H(3)(OMe)(2)-3,4)(2)] [P(wedge)P = dcpm (5), dppm (6)], were synthesized. The low-energy emission of the mercaptocrown ether-containing gold(I) complexes are tentatively assigned as originated from states derived from a S --> Au ligand-to-metal charge transfer (LMCT) transition. The crown ether-containing gold(I) complexes showed specific binding abilities toward various metal cations according to the ring size of the crown pendants. Spectroscopic evidence was provided for the metal-ion-induced switching on of the gold...gold interactions upon the binding of particular metal ions in a sandwich binding mode.
authors.affiliation: Open Laboratory of Chemical Biology, Institute of Molecular Technology for Drug Discovery and Synthesis, Centre for Carbon-Rich Molecular and Nanoscale Metal-Based Materials Research, University of Hong Kong, Pokfulam Road, Hong Kong SAR, P.R. China.
authors.forename: Chi-Kwan
authors.initials: CK
authors.lastname: Li
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Lu
authors.forename: Keith Man-Chung
authors.initials: KM
authors.lastname: Wong
authors.forename: Chui-Ling
authors.initials: CL
authors.lastname: Chan
authors.forename: Nianyong
authors.initials: N
authors.lastname: Zhu
authors.forename: Vivian Wing-Wah
authors.initials: VW
authors.lastname: Yam