Cr(III) system nitrate is made by dissolving 0-50 (25-50) degrees C, Cr(III) nitrate in at least one solvent being a 1-4C aliphatic alcohol or tetrahydrofuran, and maintaining the Cr(III) nitrate in soln. until equilibrium, the system contg sufficient water to coordinate with the Cr(III) atoms, there being not more than 10 wt.% water based on final soln. The process may be started using a conc. aq. soln of CrO3 and a reducing agent, and 2-3 moles HNO3, per mole CrO3, the mixt. contg. 10% water. To form complexes, a carboxylic acid or esters thereof may be added to the soln.
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