Local solvent properties of imidazolium-based ionic liquids

Autor(es)

Veldhorst, Arno A. ; Faria, Luiz F. O. ; Ribeiro, Mauro C. C.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MOLECULAR LIQUIDS; v. 223, p. 283-288, NOV 2016.
• Citações Web of Science: 5

Resumo

Solubility parameters such as Hildebrand's solubility parameter or its square, the cohesive energy density ced are often not able to predict solubilities of organic compounds in ionic liquids accurately. It has been suggested that this is an effect of the structural heterogeneity that many ionic liquids exhibit due to the non-polar alkyl chains forming separate domains from the charged parts of the cation and the anion. We here calculated the partial volumes of the polar and non-polar domains in Molecular Dynamics simulations of several 1-alkyl-3-methylimidazolium nitrates and 1-octyl-3-methylimidazolium hexafluorophosphate. We used these partial volumes to calculate the ced of the polar and non-polar domains. For 1-octyl-3-methylimidazolium nitrate the internal pressures Pi of the domains were also calculated. Our results show that ced and 1); are indeed very different in the domains, and that the domains containing the hydrophobic alkyl chains have solvent parameters similar to alkanes. For the domains that contain the charged part of the ions, ced and P-i are much higher, and P-i is comparable to what is found for high temperature molten salts. The results provide a possible explanation why solubility parameters seem incorrect for many ionic liquids, and may be useful in estimating more useful values using computer simulations. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 12/13119-3 - Espectroscopia vibracional em fases condensadas
• Beneficiário: Mauro Carlos Costa Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• 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: 14/13134-8 - Estudo por simulação computacional de heterogeneidade de stress em líquidos iônicos
• Beneficiário: Arnold Adriaan Veldhorst
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado