Mechanism of Hydrolysis of the Metal-Carbon Bond in α-Hydroxyalkyl-Chromium(III) Complexes. Effect of Nonparticipating Ligands

The specific rates of reaction of the free radicals -Ch₂OH, -CH(CH3)OH, and -C(CH3)2OH with [Cr11(edta)]2-, [CrII(nta)]-, and trans-[(l,4,8,12-tetraazacyclopentadecane)(h₂0)2CrH]2+ are reported and compared with the analogous reactions with Cr(h₂0)62+. The spectra of the α-hydroxyalkyl-chromium(III) complexes thus formed are reported and discussed. The rates of hydrolysis of the latter complexes are reported as well as that of cis-[(nta)(h₂0)Crm-CH3]~. The results point out that the electrophile in these hydrolysis reactions is a solvent water molecule and not a cis aqua ligand as earlier suggested. The effects of the pH of the solution and the addition of acetate on the hydrolysis reactions are reported and discussed.