Water assisted reaction mechanism of OH− with CCl4 in aqueous solution – Hybrid quantum mechanical and molecular mechanics investigation

The OH−(H2O) + CCl4 reaction in aqueous solution was investigated using the combined quantum mechanical and molecular mechanics approach. The reaction mechanism of OH−(H2O) + CCl4 consists of two concerted steps – formation of OH− in the favorable attack conformation via the proton transfer process, and the nucleophilic substitution process in which the newly formed OH− attacks the CCl4. The free energy activation barrier is 38.2 kcal/mol at CCSD(T)/MM level of theory for this reaction, which is about 10.3 kcal/mol higher than that of the direct nucleophilic substitution mechanism of the OH− + CCl4 reaction in aqueous solution.