Preparation and characterization of 1,2-dimethylimidazolium quaternary salts (new ionic liquids)

Abstract

Ionske tekućine su soli koje imaju nisko talište (<100 °C) te predstavljaju značajan potencijal za industrijsku primjenu kao “zelena“ zamjena za štetna hlapljiva organska otapala. Posebno se imidazolijeve ionske tekućine upotrebljavaju u širokom spektru zbog njihovih atraktivnih fizikalnih i kemijskih svojstava. U ovom je radu krajnji cilj bio sintetizirati nove kvaterne spojeve 1,2-dimetilimidazola. Ovi spojevi su pripravljeni reakcijom 1,2-dimetilimidazola s vodikovim peroksidom pri čemu je dobiven spoj 1,2-dimetilimidazol-N-oksid [1], koji je potom preveden u spojeve 1-butoksi-2,3-dimetilimidazolijev bromid [2] i 1-(2-hidroksietiloksi)-2,3-dimetilimidazolijev klorid [3]. Struktura novih, do sada neobjavljenih, spojeva [1]-[3] određena je pomoću podataka dobivenih IR-spektroskopijom te 1H- i 13C- nuklearno-magnetskom rezonancijom.Ionic liquids are salts with low melting point (<100 °C) having enormous potential for industrial use as “green” replacements for harmful volatile organic solvents. Especially, imidazolium ionic liquids are used in a wide variety of applications due to their attractive physical and chemical properties. In this final work, the ultimate goal was the synthesis of new quaternary salts of 1,2-dimethylimidazole. These compounds are prepared by reaction of 1,2-dimethylimidazole with hydrogen peroxide into 1,2-dimethylimidazole-N-oxide [1] which was further transformed into compounds 1- butoxy-2,3-dimethylimidazolium bromide [2] and 1-(2-hydroxyethyloxy)-2,3- dimethyilimidazolium chloride [3]. Structures of novel, yet unpublished compounds [1]-[3] were determined according to the data obtained by IR-spectroscopy as well as 1H- and 13 C-nuclear magnetic resonance