Ionic compounds having a freezing point of no more than 50 DEG C, formed by the reaction of at least one amine salt of the formula R R R R N X (I) with at least one hydrated salts, which is a chloride, nitrate, sulphate or acetate of Li, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Bi, La or Ce; wherein R , R and R are each independently a C1 to C5 alkyl or a C6 to C10 cycloalkyl group, or wherein R and R taken together represent a C4 to C10 alkylene group, thereby forming with the N atom of formula (I) a 5 to 11 membered heterocyclic ring, and wherein R is hydrogen, or phenyl, or C1 to C12 alkyl or cycloalkyl group, optionally substituted with at least one group selected from OH, Cl, Br, F, I, phenyl, NH2, CN, NO2, COOR , CHO, COR and OR , wherein R is a C1 to C10 alkyl or cycloalkyl group, and X is an anion capable of being complexed by the said hydrated salt. The compounds are useful as solvents, electrolytes, and catalyts, and have particular application in solvents/electrolytes for metal plating and electropolishing processes, in particular in chromium plating.