Ionic liquids in green chemistry: catalytic reaction of cyclic ...

L.W. Wijayanti et al. Proceeding of The International Seminar on Chemistry 2008 (pp. 356-362)Jatinangor, 30-31 October 2008Table 5 List of variation of Henry’s law coefficient with temperature of 1-3-dialkylimidazolium dialkylphosphate ionic liquidsCompound T/K H 21 /MPa Error a313.15 10.64 0.12[MMIM][Me 2 PO 4 ] 323.15 12.72 0.03333.15 15.22 0.15313.15 6.99 0.03[EMIM][Et 2 PO 4 ] 323.15 8.12 0.04333.15 9.66 0.02313.15 4.98 0.02[BMIM][Bu 2 PO 4 ] 323.15 5.76 0.02333.15 6.85 0.03a Standard errors of the isotherm slopes10 3 x240353025201510500 50 100 150 200p/kPaFigure 4 Solubility CO 2 in [BMIM][Bu 2 PO 4 ] at (●)313.15 K, (■) 333.15 K, and (▲) 323.15 Kat atmospheric pressureIn our experiments, the Henry’s law coefficient at aspecified temperature was estimated from the slope ofa linear fit of the CO 2 solubility in mole fractionversus fugacity. The Henry’s law coefficients atvarious temperatures and the standard error of theisotherm slopes are given in the Table 5. As can beseen, all of the Henry’s law.ConclusionsA series of ionic liquid-based imidazolium zinctetrahalide and (1-R-3-methylimidazolium) 2 ZnX 2 Y 2 ,were prepared by reacting ZnX 2 with (1-R-3-methylimidazolium)Y.The single crystal X-ray structural analysis andelemental analysis of (1,3-dimethylimidazolium) 2ZnBr 2 Cl 2 revealed that two imidazolium cations werepaired with a dibromodichloro zincate dianion.The catalytic activities of imidazolium zinctetrahalide were evaluated for the coupling reactionsof epoxides and CO 2 , and the effects of halide ions,imidazolium cations, temperature and pressure wereinvestigated. The catalytic activity of (1-R-3methylimidazolium) 2 ZnX 2 Y 2 was found to increasewith increasing nucleophilicity of halide ion. But, thesubstitution on the imidazolium cation showed anegligible effect on the catalytic activity. Theformation of cyclic carbonate was strongly dependenton the temperature but independent of the pressure ofCO 2 . The reactivity of alkylene oxide was greatlyaffected by the substituent at the carbon atom of theepoxide. Ethylene oxide and alkylene oxides with lessbulkier substituents produced corresponding alkyleneoxides in high yields. However, alkylene oxides withbulky or electron-withdrawing substituents aroundepoxide groups gave much lower yields of alkylenecarbonates.The CO 2 solubility increases linearly with pressurein all of the dialkylimidazolium dialkylphosphateionic liquids and decreases as temperature increases.It means that dialkylimidazolium dialkylphosphatehave capability to capture CO 2 through physicalinteraction.AcknowledgementsThis work was supported by the Ministry ofEnvironment in Korea and presented by Ms. LuciaWiwid Wijayanti, M.SiReferencesA. Behr, Carbon Dioxide Activation by MetalComplexes, VCH, New York, 1988.D.J. Darensbourg, M.W. Holtcamp, Coord. Chem.Rev. (1996) 153.T. Kim, S. Vijayalakshmi, S. Son, S. Ryu, J. Kim, J.Ind. Eng. Chem. 9 (2003) 481–487.B. Sea, Y. Park, K. Lee, J. Ind. Eng. Chem. 8 (2002)290–296.M. Aresta, E. Quaranta, ChemTech. Mar. (1997) 32–40.A.G. Shaikh, Chem. Rev. 96 (1996) 951–976.D. Lee, J. Hur, B. Kim, S. Park, D. Park, J. Ind. Eng.Chem. 9 (2003) 513–517.J.J. Lagowski, The Chemistry of NonaqueousSolvents, Academic Press, New York, 1976.M. Inaba, Z. Siroma, A. Funabiki, M. Asano,Langmuir 12 (1996) 1535–1540.361