High-Accuracy Vapor Pressure Data of the Extended [C(n)C(1)im][Ntf(2)] Ionic Liquid Series: Trend Changes and Structural Shifts

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Marisa A A Rocha (Author) Other; Carlos F R A C Lima (Author) Other; Ligia R Gomes (Author) Other; Bernd Schroeder (Author) Other; Joao A P Coutinho (Author) Other; Isabel M Marrucho (Author) Other; Jose M S S Esperanca (Author) Other; Luis P N Rebelo (Author) Other; Karina Shimizu (Author) Other; Jose N C Canongia Lopes (Author) Other; Luis M N B F Santos (Author) FCUP

Journal

Title: Journal of Physical Chemistry B

Vol. 115 No. 24

Pages: 10919-10926

ISSN: 1520-6106

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 188 Citations

Scopus - 198 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-MGE

DOI: 10.1021/jp2049316

Abstract (EN): For the first time, two distinct trends are clearly evidenced for the enthalpies and entropies of vaporization along the [C(n)mim][Ntf(2)] ILs series. The trend shifts observed for Delta H-g(1)m degrees and Delta S-g(1)m degrees, which occur at [C(6)mim] [Ntf(2)], are related to structural modifications. The thermodynamic results reported in the present article constitute the first quantitative experimental evidence of the structural percolation phenomenon and make a significant contribution to better understanding of the relationship among cohesive energies, volatilities, and liquid structures of ionic liquids. A new Knudsen effusion apparatus, combined with a quartz crystal microbalance, was used for the high-accuracy volatility study of the 1-alkyl-3-methylirnidazolium bis(trifluoromethylsulfonyl)imide series ([C(n)mim][Ntf(2)], where n = 2, 3, 4, 5, 6, 7, 8, 10, 12). Vapor pressures in the (450-500) K temperature range were measured, and the molar standard enthalpies, entropies, and Gibbs energies of vaporization were derived. The thermodynamic parameters of vaporization were reported, along with molecular dynamic simulations of the liquid phase structure, allowing the establishment of a link between the thermodynamic properties and the percolation phenomenon in ILs.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8