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  • Fluorescent quinolizinium ionic liquids (salts) with unexpectedly high quantum yields up to >99%
  • 更新时间:2014-04-10;信息类型:SCI论文
  • Quinolizinium ionic liquids (salts) featuring an unbranched cation core have been prepared, characterized and found to show extremely high fluorescence quantum yields in solution (Ff > 99%, lem near 334 nm) and bright cyan fluorescence in molten state (lem near 465 nm).
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/141.html
  • Ionic liquidized-naphthalenesulfonamide: successful fabrication of liquid fluorescent materials
  • 更新时间:2014-04-10;信息类型:SCI论文
  • A new class of liquid fluorescent organic salts was designed and prepared through via a strategy of ionic liquidization. These new ionic liquid materials exhibited strong green fluorescence and remarkable solvent-dependent photoluminescence under UV irradiation. Their physicochemical properties, especially the fluorescent behaviour, were studied intensively.
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/140.html
  • Photochromism of Spiropyran in Ionic Liquids: Enhanced Fluorescence and Delayed Thermal Reversion
  • 更新时间:2014-04-10;信息类型:SCI论文
  • Photochromism of spiropyran and thermal reversion of MC in a series of imidazolium-based ionic liquids (ILs) were investigated via fluorescence and UV-vis absorption spectra. The fluorescence emission maxima (λem) of the colored merocyanine (MC) form is polarity dependent in all ILs and fluorescence intensity enhancement was first observed in ILs with respect to that observed in organic solvents (e.g., in [HOMIm][PF6], nearly 32-fold enhancement than ethanol). Moreover, the thermal decay of MC in all ILs is uniformly first order, and in comparison with polar solvents possessing comparable polarity (such as ethanol and acetonitrile), a significant retardation of the decay rate and increase of half-lifetime of MC form was observed, in particular at elevated temperature (e.g., at 313 K, MC decay with k of 5.19 × 10-4 and 34.7 × 10-4 s-1 in [BMMIm][BF4] and ethanol, respectively). Abnormal thermodynamics of the thermal decay of MC in ILs were observed, activation energies in less polar ILs (88-97 kJ mol-1) have a larger value than in polar ILs (70-82 kJ mol-1), opposite that in organic solvents (70-80 kJ mol-1 in nonpolar solvents and around 100 kJ mol-1 in polar solvents), and all ILs exclusively exhibit minus activation entropies (-85.4 to -24.5 J K-1 mol-1), similar to that of nonpolar solvents. Desolvation due to the conformational change during the thermal reversion between MC and the transition state may be the key to interpret this experimental result.
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/119.html
  • Greatly enhanced fluorescence of dicyanamide anion based ionic liquids confined into mesoporous silica gel
  • 更新时间:2014-04-09;信息类型:
  • 1-Ethyl-3-methylimidazolium dicyanamide EMImN(CN)2 and S-ethyltetrahydrothiophene dicyanamide EThN(CN)2 physically confined into mesoporous silica gel with pore sizes of 6–8 nm (IL-sg) were synthesized according to a proper sol–gel process. Greatly enhanced fluorescence emissions of dicyanamide based ILs after being confined were exhibited.
  • 链接地址:http://www.ionike.com/download/article/2014-04-09/107.html