The synthesis of nitrile-functionalized azepanium ionic liquids such as 1-butyl-1-(2-cyano-ethyl)-azepanium bromide, C4CNAzpBr, 1-butyl-1-(2-cyano-ethyl)azepanium trifluoroacetate, C4CNAzpTFA, 1-butyl-1-(2-cyano-ethyl)-azepanium methanesulfonate C4CNAzpCH3SO3, 1-butyl-1-(2-cyano-ethyl)azepanium trifluoromethanesulfonate C4CNAzpCF3SO3, 1-butyl-1-(2-cyano-ethyl)azepaniummethanesulfateC4CNAzpCH3SO4,1-butyl-1-(2-cyano-ethyl) azepanium p-toluenesulfonate C4CNAzpPTS were performed. The synthesis of ionic liquids was performed in three steps. 1H, 13C and CHNS elemental analysis were used to characterize the synthesized ionic liquids. The thermal stability, melting point and glass transition temperature of the ionic liquids were determined. The nitrile-functionalized ionic liquids showed good thermal stability. © 2016