The phases, ion crystal packing and thermal properties of the N-alkyl-N-methylpyrrolidinium and piperidinium bis(trifluoromethanesulfonyl) imide (PYR1RTFSI and PIP1RTFSI (subscript R ≤ 1 for methyl and = 2 for ethyl), respectively) salts are compared using powder and single-crystal x-ray diffraction (XRD) and differential scanning calorimetry (DSC). The crystal structure of PIP12TFSI has been determined at 123 K. The salt crystallizes in the triclinic space group with Z ≤ 8. Structural data are also reported for PYR11TFSI at 153 K and PIP 12TFSI at 223 K. PIP11TFSI has identical ion crystal packing to the analogous pyrrolidinium salt PYR11TFSI. Since increasing the cation alkyl chain length to propyl or butyl (R ≤ 3 or 4) reduces the melting point of the salts below room temperature, this study may provide valuable insight into why these pyrrolidinium and piperidinium salts form room-temperature ionic liquids. © IOP Publishing Ltd.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
Henderson, W. A., Young Jr., V. G., Pearson, W., Passerini, S., De Long, H. C., & Trulove, P. C. (2006). Thermal phase behaviour of N-alkyl-N-methylpyrrolidinium and piperidinium bis(trifluoromethanesulfonyl)imide salts. Journal of Physics Condensed Matter, 18(46), 10377 - 10390. . https://doi.org/10.1088/0953-8984/18/46/006