Ionic liquids crystal polymorphism

Holbrey, J. D., Reichert, W. M., Nieuwenhuyzen, M., Johnston, S., Seddon, K. R., and Rogers, R. D., Crystal polymorphism in l-butyl-3-methylimidazolium halides Supporting ionic liquid formation by inhibition of crystallization, Chem. Commun., 1636-1637, 2003. 

Hayashi, S., Ozawa, R., and Hamaguchi, H., Raman spectra, crystal polymorphism, and structure of a prototype ionic-liquid [bmimJGl, Chem. Lett., 32, 498-499,2003. 

In terms of supramolecular chemistry, imidazolium type ionic liquids are interesting because they are excellent C-H hydrogen bond donors. The X-ray crystal structure of bmim Cl shown this property clearly with C-Cl 3.39 A, Figure 13.24. Interestingly, two different polymorphic forms of this material are known depending on whether it is crystallised from the molten ionic liquid for from solution,... 

Several new methods of crystal growth and polymorph search and form control were discussed at the recently held International Workshop on Crystal Growth of Organic Materials (CGOM). Crystallization in gels and ionic liquids and the mechanism for crystal growth in the presence of impurities/imposter molecules are some new methods for further reading. 

Among the earliest ionic liquids for which single-crystal characterisation of polymorphs has been reported are 1,3-dialkylimidazolium chlorides and bromides [230, 566]. Monoclinic and orthorhombic forms of [C4inim]Cl are associated with differences in butyl conformation, with a conputational study [567] suggesting that the free energy difference associated with a single... 

Yoshimura, Y, Abe, H., Imai, Y, Takekiyo, T. and Hamaya, N., Deconpression-induced crystal polymorphism in a room-tenperature ionic liquid, JV,JV-diethyl-iV-methyl-iV-(2-methoxyethyl) ammonium tetrafluoroborate, J. Phys. Chem. B117 (11), 3264-3269 (2013). 

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