title: Anion binding and luminescent sensing using cationic ruthenium(II) aminopyridine complexes.
abstract: The synthesis of a series of ruthenium(II) based anion sensors of the type [Ru(eta(6)-C(6)H(4)MeCHMe(2))Cl(L)(2)][BF(4)] (2) is reported in which ligand L represents a series of substituted pyridinylmethyl-amine derivatives. The carbazole based ligand L(3) exhibits a fluorescent intraligand charge-transfer (ILCT) state that is quenched by ligand-to-metal charge transfer (LMCT) upon coordination to ruthenium in the 1:1 complex [Ru(eta(6)-C(6)H(4)MeCHMe(2))Cl(2)(L(3))] (1 c). The 1:2 complex 2 c is fluorescent, however, and acts as a fluorescent anion sensor because of the mixing of an anion-dependent charge-transfer component into the excited state. The 1:2 complexes of type 2 all exhibit interesting low symmetry (1)H NMR spectra that also are a useful handle on anion complexation. The electronic structures of L(3), 1 c and 2 c have been probed by time-dependent DFT calculations.
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham, UK.
authors.forename: Sara Jane
authors.initials: SJ
authors.lastname: Dickson
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Paterson
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Willans
authors.forename: Kirsty M
authors.initials: KM
authors.lastname: Anderson
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Steed