MECHANISM OF SOLID LIQUID INTERFACIAL REACTIONS - THE HYDROLYTIC DISSOLUTION OF SOLID TRIPHENYLMETHYL CHLORIDE IN AQUEOUS-SOLUTION/

The reaction between solid triphenylmethyl chloride (TPMCl) and water, TPMCl(s) + H2O(1)-->TPMOH(aq) + H+(aq) + Cl-(aq), where TPMOH is trip henylmethyl alcohol, has been investigated using the channel flow cell method. It is found that hydrolysis proceeds via a direct heterogeneo us fashion whereby the reaction occurs at the solid-liquid interface r ather than in solution after the prior dissolution of TPMCl. Kinetic p arameters are reported including the effect of ionic strength. Further , using experiments conducted with different surfaces of single crysta ls of TPMCl, it is shown that the rate of the interfacial process depe nds on the availability of exposed chlorine atoms in the reacting crys tal plane. In situ atomic force microscopic studies indicate that the TPMCl surface, once in contact with water, is covered rapidly by a por ous product layer, However, the latter provides a negligible effect on the reaction rate because of its high porosity.