Hydrogen-bond rich ionic liquids with hydroxyl cationic tails

To investigate if the amphiphilic feature exhibited in ionic liquids (ILs) with nonpolar cationic tails still exists in ILs with polar tails, by performing molecular dynamics simulations for 1-(8-hydroxyoctyl)-3-methyl- imidazolium nitrate (C-OH) and 1-octyl-3-methyl-imidazolium nitrate (C-8), we found that, in C-OH, cationic tail groups can no longer aggregate to form separated nonpolar tail domains, instead hydroxyl groups form a rich number of hydrogen bonds with other groups, indicating that the hydroxyl substituent changes the IL system from an amphiphilic liquid to a polar liquid. Due to the large amount of hydrogen bonds, C-OH has slower dynamics than C-8. (c) 2013 Elsevier B.V. All rights reserved.