Syntheses、Fluorescence And Physicochemical Properties Of Functional Lanthanide-Containing Ionic Liquids

Ionic liquids (ILs) have several unique properties including generally negligible vapor pressure, good electric conductivity, wide liquid ranges, large electrochemical window, and their potential as solvents for liquid-liquid extraction, which make them widely used in many physical and chemical fields.Metal-containing ionic liquids based on imidazolium salts are promising new materials which can favorably combine the properties of ionic liquids with additional magnetic, spectroscopic and catalytic properties depending on the metal incorporated. Recently, several types of ionic liquids containing lanthanide have been reported as promising new materials including luminescent materials, magnetic materials, and energetic materials.1. Two new lanthanide-based room temperature ionic liquids [Bmim][Ln(NO3)4] (Bmim=1-buty-3-methylimidazolium; Ln=Dy, Sm) were synthesized by 1-butyl-3-methylimidazolium, bromobutane, AgNO3, Dy(NO)3·6H2O and Sm(NO)3·6H2O. The structures of the ionic liquids were characterized by infrared spectra (IR), proton nuclear magnetic resonance (’H NMR), mass spectrometry (MS) and thermogravimetric analysis(TGA).2. The luminescent properties of the two compounds were investigated at room temperature. The Dy(Ⅲ)-based room-temperature ionic liquid had an intense kelly emission and the Sm(Ⅲ)-based room-temperature ionic liquid had an intense red emission They showed good luminescent properties and could be used as good soft luminescent materials. This kind of hydrostable and eco-friendly ionic liquids were firstly used to explore the sensing behavior for Fe3+ ions, exhibited a highly specific recognition and not interfered by the following common mental ions:Ca2+, Al3+, Zn2+ Cu2+, Pb2+, Hg2+, Cd2+, Co2+, Fe2+, Ni2+ and Cr3+. These features will make lanthanide-based room temperature ionic liquids have an outstanding application prospect in "green" fluorescent sensor and be widely used in actual detection.3. The standard addition method (SAM) was applied to these measurements of the Dy(Ⅲ)-based room-temperature ionic liquid. The values of density(ρ)、surface tension(y), refractive index(nD>) and conductivity(k) were measured at the temperature range of (298.15 to 328.15±0.01) K. The standard molar entropy and lattice energy of the Dy(Ⅲ)-based ionic liquid at 298.15K were calculated by Glasser’s theory. A new concept-molar surface Gibbs free energy (gs) was put forward. In terms of the concept of molar surface Gibbs free energy (gs), a new Eotvos equation was obtained. The gs, critical temperature (Tc) and Eotvos empirical parameter related to polarity(kE), were also obtained. The new Eotvos equation can be used to predict the surface tension and the predicted values of the surface tension of [Bmim][Dy(NO3)4] are in good agreement with the corresponding experimental ones. The thermal expansion coefficient(α) of [Bmim][Dy(NO3)4], were calculated by surface tension throughing interstice model. Then we found that the calculated values and the experimental values are in good agreement. Meanwhile, the molar polarization and polarizability were calculated by the values of refractive index of the Dy(III)-based ILs. The relationship between the conductivity and temperature were investigated by the equation of Arrhenius and VTF. Meanwhile the molar conductivity was gotten by the value of conductivity. The values of diffusion coefficient were calculated by the equation of Nernst-Einstein.