title: Synthesis, structure, and characterization of chromo(fluoro)ionophores with cation-triggered emission based on N-methylaza-crown-ether styryl dyes.
abstract: Novel 2-benzothiazole-, 4-pyridine-, and 2- and 4-quinoline-based styryl dyes containing an N-methylbenzoaza-15(18)-crown-5(6)-ether moiety were synthesized. A detailed electronic spectroscopy study revealed high performance of these compounds as optical molecular sensors for alkali and alkaline-earth metal cations. They were shown to considerably surpass analogous chromoionophores based on N-phenylaza-crown ethers regarding both the ionochromism and the cation-binding ability. In addition, they act as fluorescent sensors for the metal cations by demonstrating cation-triggered emission. Upon complexation with Ba(2+), the fluorescence enhancement factor reaches 61. The structural features of dyes and their metal complexes were studied by NMR spectroscopy and X-ray diffraction. The high degree of macrocycle preorganization was found to be one of the factors determining the high cation-binding ability of the sensor molecules based on N-methylbenzoaza-crown ethers.
authors.affiliation: Photochemistry Center, Russian Academy of Sciences , ul. Novatorov 7A-1, Moscow 119421, Russian Federation.
authors.forename: Sergey P
authors.initials: SP
authors.lastname: Gromov
authors.forename: Svetlana N
authors.initials: SN
authors.lastname: Dmitrieva
authors.forename: Artem I
authors.initials: AI
authors.lastname: Vedernikov
authors.forename: Nikolay A
authors.initials: NA
authors.lastname: Kurchavov
authors.forename: Lyudmila G
authors.initials: LG
authors.lastname: Kuz'mina
authors.forename: Sergey K
authors.initials: SK
authors.lastname: Sazonov
authors.forename: Yuri A
authors.initials: YA
authors.lastname: Strelenko
authors.forename: Michael V
authors.initials: MV
authors.lastname: Alfimov
authors.forename: Judith A K
authors.initials: JA
authors.lastname: Howard
authors.forename: Evgeny N
authors.initials: EN
authors.lastname: Ushakov
mesh_terms: D002412:Cations / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D056831:Coordination Complexes; D043844:Crown Ethers / Q000737:chemistry*; D007476:Ionophores / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013343:Styrenes / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D002412:Cations; D004396:Coloring Agents; D056831:Coordination Complexes; D043844:Crown Ethers; D007476:Ionophores; D013343:Styrenes