2-PHASE CATALYTIC NBR HYDROGENATION BY RUHCL(CO)(PCY3)(2) IMMOBILIZEDIN 1-BUTYL-3-METHYLIMIDAZOLIUM TETRAFLUOROBORATE MOLTEN-SALT

RuHCl(CO)(PCy3)(2) (1) dissolved in 1-butyl-3-methylimidazolium tetraf luoroborate (2) molten salt is able to reduce selectively NBR to HNBR under hydrogen partial pressures between 10 and 40 bar at 100-160 degr ees C in a typical two-phase catalytic reaction. Reaction rates betwee n 0.059 (mmol Ru)(-1).min(-1) and 1.65 (mmol Ru)(-1.)min(-1) were obta ined depending on the reaction parameters and increasing with the volu me of the molten salt. The overall process has an apparent activation energy of 47 +/- 3 kJ.mol(-1). The recovered ionic catalyst solution c an be reused several times without significant changes in the catalyti c performance (selectivity and activity).