Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

12-23-2004

Journal or Book Title

Journal of the American Chemical Society

Volume

127

Issue

2

First Page

593

Last Page

604

DOI

10.1021/ja046521u

Abstract

Thirty-nine geminal dicationic ILs were synthesized and characterized in terms of their surface tensions, densities, melting points, refractive indices, viscosities, and miscibilities with a polar and nonpolar solvent. Two imidazolium or pyrrolidinium cations were joined via different length hydrocarbon linkage chains (from 3 to 12 carbons long). The various geminal dications were paired with up to four different anions. The effect of the dication type, linkage chain, alkyl substituents, and anion type on the physicochemical properties of these compounds was examined. Among the more interesting findings for this class of compounds was that their liquid and thermal stability ranges generally exceeded those of the more conventional, better known ILs. Indeed, this range was from −4 to >400 °C for one of the pyrrolidinium-based geminal dicationic liquids. X-ray crystallography of the smaller solid ionic compounds indicated that there may be a correlation between the configurational degrees of freedom of the ILs and their melting points/glass transition temperatures. In one case, the crystal structure showed that a dicationic moiety had three distinct conformations in an asymmetric unit cell. The solvation properties of the geminal dicationic ILs tend to be similar to those of their monocationic analogues.

Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 127 (2005): 593, doi: 10.1021/ja046521u. Copyright 2005 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Share

COinS