KINETICS AND THERMODYNAMICS OF THE RACEMIZATION OF TRIS(L-VALINATO)CHROMIUM(III) COMPLEXES IN N,N-DIMETHYLFORMAMIDE

Racemization between fac-Lambda-(+)(546)- and fac-Delta-(-)(546)-[Cr(V al)(3)] (1 and 2) was studied in N, N-dimethylformamide (DMF). These c omplexes were preferentially converted into bis-type complexes, Lambda -(+)(546)- and Delta-(-)(546)-[Cr(val)(2)(val- N)DMF] (4 and 3), and a n equilibrium comprising these four species was established. In order to determine the equilibrium constants, rate constants, and activation parameters in a proposed square-network reaction system, the mole fra ctions of four species with time in reacting solutions at 40, 50, and 60 degrees C were determined by liquid chromatography. The reaction pr ocesses are discussed based on the obtained values.