Exploring the phase diagram of the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesufonyl)imide

Autor(es)

Lima, Thamires A. ^[1] ; Faria, Luiz F. O. ^[1] ; Paschoal, Vitor H. ^[1] ; Ribeiro, Mauro C. C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Lab Espectroscopia Mol, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Molecular Structure; v. 1183, p. 149-156, MAY 5 2019.
• Citações Web of Science: 1

Resumo

X-ray diffraction and Raman scattering measurements of the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesufonyl)imide, {[}Pyrr(1,4)]{[}NTf2], were performed in a wide range of temperature and pressure. Pressure dependence of glass transition T-g(p), cold-crystallization T-cc(p), and melting T-m(p) temperatures were obtained from atmospheric pressure up to ca. 2.0 GPa. The temperature dependence of Raman spectra within the T-cc < T < T-m range at atmospheric pressure unveils conformational dynamics of {[}Pyrr(1)(,4)](- )while {[}NTf2](-) remains in the transoid conformation characteristic of the crystal. The different pressure dependence of T-cc(p) and T-m(p) implies that these curves merge at ca. 330 K and 1.0 GPa. Upon the assumption that the T-g(p) curve belongs to isochronous states, T-g(p) is discussed in terms of thermodynamic scaling using low-temperature and high-pressure extrapolations of an empirical equation of state. The ratio between constant volume and constant pressure activation energies for viscous flow, E-v/E-p, increases only slightly in the pressure range investigated in this work. The results obtained under simultaneous variation of temperature and pressure highlight the complex interplay between glass transition and crystallization of {[}Pyrr(1)(,4)]{[}NTf2]. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 15/05803-0 - Estrutura de líquidos iônicos em alta pressão
• Beneficiário: Luiz Felipe de Oliveira Faria
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/07516-8 - Dinâmica coletiva de líquidos iônicos
• Beneficiário: Vitor Hugo Paschoal
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 14/15049-8 - Estudo por espectroscopia Raman da transição vítrea de líquidos iônicos em alta pressão.
• Beneficiário: Thamires Andrade Lima
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/21070-5 - Espectroscopia vibracional com resolução espacial
• Beneficiário: Mauro Carlos Costa Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Temático