title: Salen-based chiral fluorescence polymer sensor for enantioselective recognition of α-hydroxyl carboxylic acids.
abstract: (R,R)-Salen-based chiral polymer P-1 was synthesized by the polymerization of 5,5'-((2,5-dibutoxy-1,4-phenylene)bis(ethyne-2,1-diyl))bis(2-hydroxy-3-(piperidin-1-ylmethyl) benzaldehyde (M-1) with (1R,2R)-cyclohexane-1,2-diamine (M-2) via nucleophilic addition- elimination reaction, and (R,R)-salan-based polymer P-2 could be obtained by the reduction reaction of P-1 with NaBH(4). (R,R)-Salen-based chiral polymer P-1 can exhibit greater fluorescence enhancement response toward (l)-α-hydroxyl carboxylic acids, and the value of enantiomeric fluorescence difference ratio (ef) can reach as high as 8.41 for mandelic acid and 6.55 for lactic acid. On the contrary, (R,R)-salan-based chiral polymer P-2 shows obvious fluorescence quenching response toward α-hydroxyl carboxylic acids. Most importantly, (R,R)-salen-based polymer P-1 can display bright blue fluorescence color change in the presence of (l)-α-hydroxyl carboxylic acids under a commercially available UV lamp, which can be clearly observed by the naked eyes.
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Fengyan
authors.initials: F
authors.lastname: Song
authors.forename: Guo
authors.initials: G
authors.lastname: Wei
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.forename: Jiemin
authors.initials: J
authors.lastname: Jiao
authors.forename: Yixiang
authors.initials: Y
authors.lastname: Cheng
authors.forename: Chengjian
authors.initials: C
authors.lastname: Zhu