Hits:

Indexed by:期刊论文

Date of Publication:2009-01-01

Journal:NEW JOURNAL OF CHEMISTRY

Included Journals:SCIE、Scopus

Volume:33

Issue:3

Page Number:653-658

ISSN No.:1144-0546

Abstract:Three chemosensors DN1, DN2 and DN3, incorporating dansyl dye as a fluorophore and various carboxhydrazones as ionophores, are reported. DN1 contains a pyridine-carboxhydrazone tridentate coordination site, forming a 2: 1 stoichiometric complexation species with Cr(3+), and exhibits selectivity for Cr(3+) over alkali and alkaline earth metals and most first-row transition metals in aqueous media. DN1 displays high quantum yield (Phi = 0.86) and fluorescence enhancement following Cr(3+) coordination within a wide pH range. DN2 contains a 8-hydroxyquinoline-carboxhydrazone tetradentate metal-binding moiety, forming a 1:1 complex with Cr(3+). DN2 also exhibits significantly fluorescence enhancement but a much lower quantum yield following Cr(3+) binding in aqueous solution. In contrast, their congener DN3, having a salicyl-carboxhydrazone tridentate binding site, does not exhibit any significant fluorescence variation following Cr(3+) binding. These results demonstrate that the hydroxyl group is an important factor influencing the fluorescence response to Cr(3+) in aqueous media.