Polyacrylates containing dansyl semicarbazide units sensitive for some structures in solution and film

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• 作者：Emil C. Buruiana ; Andreea L. Chibac ; Tinca Buruiana
• 关键词：Copolymerization ; Polyacrylates ; Dansyl semicarbazide ; Fluorescence
• 刊名：Journal of Photochemistry and Photobiology A: Chemistry
• 出版年：2010
• 出版时间：25 June 2010
• 年：2010
• 卷：213
• 期：2-3
• 页码：107-113
• 全文大小：739 K

文摘

Two dansylated copolymers have been synthesized by free radical polymerization of N-methacryloyloxyethylcarbamoyl-5-(dimethylaminonaphthalene-1-sulfonohydrazine) (DnsSA) and N-dodecylacrylamide or methyl methacrylate with 1,1′-azobis (cyclohexanecarbonitrile) as the initiator. The structure and the chemical composition of the formed copolymers (DnsSA-DA; DnsSA-MMA) were confirmed by spectral analysis (¹H NMR, FTIR, UV/vis), thermal methods, GPC measurements, and AFM technique. Compared with DnsSA (λ_em = 525 nm/DMF; 515 nm/CHCl₃), the emission spectra of DnsSA-DA in DMF exhibited a time- and concentration-dependent monomer and excimer fluorescence (430 nm; 520 nm), while in CHCl₃ only the excimer form exists for both copolymers. The sensing ability of these copolymers in both the solvents has been investigated by fluorescence spectroscopy in tandem with quenching experiments using various metal ions (Cu²⁺, Fe²⁺, Ni²⁺) and nitroaromatics (picric acid, p-nitrotoluene, o-nitrophenol, dinitro-m-xylene, nitrobenzene), which suggested that such polymeric fluorophores could find applications for detection of some metal ions as well as nitro-derivatives in DMF solutions, the most efficient quencher being Cu²⁺ and picric acid in the case of DnsSA-DA. The fluorescence study showed that the fluorescence emission in film state can be also quenched by nitrobenzene vapors, and further, an excellent reversibility of this process was observed.