Estimates of Internal Pressure and Molar Refraction of Imidazolium Based Ionic Liquids as a Function of Temperature

• Published in: Journal of solution chemistry Vol. 37; no. 2; pp. 203 - 214
• Main Author: Kumar, Arvind
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2008; Springer
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Exact sciences and technology; General and physical chemistry; Geochemistry; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Oceanography; Physical Chemistry; Solutions; Ionic liquids; Speed of sound; Density; Refractive index; Internal pressure; Speed; Speed of sound; Refractive index; Internal pressure; Molar refraction; Pressure; Ionic liquid
• ISSN: 0095-9782; 1572-8927
• DOI: 10.1007/s10953-007-9231-5

Estimates of the internal pressure ( ∂ U / ∂ V ) T of the ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF 4 ], 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF 6 ], and 1-methyl-3-octylimidazolium tetrafluoroborate [OMIM][BF 4 ] were made from experimentally determined densities and speeds of sound in the temperature range 283.15 to 343.15 K. Values ( ∂ U / ∂ V ) T for all the ILs studied are higher than those of water and molecular organic liquids. We also measured the refractive indices n D in the temperature range 288.15 to 343.15 K and estimated the molar refraction  R M . Refractive indices of ILs were also higher than those of normal organic liquids but were comparable to those of long hydrocarbon chain organic solvents.