title: Highly Ag+ selective tripodal gold(I) acetylide-based "off-on" luminescence chemosensors based on 3(ππ*) emission switching.
abstract: Newly prepared gold(I) acetylide-based luminescent cation sensors 1c and 1d, which bear a novel three-armed flexible conformation, together with control molecule 2c, were synthesized in four steps. 1c and 1d exhibit the π → π* absorption of the acetylide ligands in fluid solutions and produce the (3)(ππ*) emission of the acetylide ligands in the solid state and degassed THF solution. The (3)(ππ*) emission of 1c in DMSO can be turned on upon addition of Ag(+). The binding ratio between 1c and Ag(+) as well as the binding constant log K were determined as 1:1 and 4.35 ± 0.12 respectively by UV-vis titration experiments. The formation of [1c·Ag](+) adduct, which leads to the appearance of new up-field peaks, was confirmed by (1)H NMR spectroscopic titrations. The control (1)H NMR titration experiments for the acetylide-free analogue 1a and single-armed analogue 2c indicate the acetylide groups and tripodal structures are responsible for the binding of Ag(+). The control experiment for tripodal gold(I) acetylide analogue 1d suggests the change of PPh3 with P(2-Py)Ph2 induces similar binding affinity toward Ag(+) but less selectivity toward Ag(+). Free 1c also exhibits the anion binding affinity toward F(-), but the Ag(+) adduct [1c·Ag](+) shows less affinity toward F(-).
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Yu-Peng
authors.initials: YP
authors.lastname: Zhou
authors.forename: En-Bao
authors.initials: EB
authors.lastname: Liu
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Hsiu-Yi
authors.initials: HY
authors.lastname: Chao
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D006046:Gold / Q000737:chemistry*; D008163:Luminescent Measurements; D009942:Organometallic Compounds / Q000737:chemistry*; D012834:Silver / Q000032:analysis* / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D012834:Silver; D006046:Gold