title: Synthesis and characterization of new coordination polymers with tunable luminescent properties generated from bent 1,2,4-triazole-bridged N,N'-dioxides and Ln(III) salts.
abstract: A new bent 1,2,4-triazole-bridged N,N'-dioxide ligand, namely, 3,5-bis(3-pyridyl-N-oxide)-4-amino-1,2,4-triazole (L2), was designed and synthesized by the oxidation of 3,5-bis(3-pyridyl)-4-amino-1,2,4-triazole with H(2)O(2) in the presence of HOAc at ambient temperatures. Eleven Ln(III)-based coordination polymers have been successfully prepared by the solution reactions of L2 with various Ln(III)-perchlorates. The structures of these new Ln(III) polymers clearly reflect the effect of the lanthanide contraction. Compounds 1-6 feature a two-dimensional net, in which the Ln(III) atoms adopt a nine-coordinate {LnO(9)} sphere due to their larger ionic radii, whereas the Ln(III) centers in the one-dimensional double-stranded chains of 7-11 with smaller ionic radii lie in a {LnO(8)} coordination environment. In addition, the tunable emission intensity was realized on 7 by controlling the type of the involved counterion on the basis of a reversible solid-state anion exchange. Such reversible solid-state anion exchange might provide an alternative approach to tuning the luminescence.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Key Lab of Molecular and Nano Probe, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Shandong Normal University, Jinan, 250014, PR China.
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Wang
authors.forename: Jun-Yan
authors.initials: JY
authors.lastname: Cheng
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Ma
authors.forename: Yu-Bin
authors.initials: YB
authors.lastname: Dong
authors.forename: Ru-Qi
authors.initials: RQ
authors.lastname: Huang