Naphthyl Chloroformate류의 가용매 분해반응에 대한 속도론적 연구

Abstract

The specific rates of the solvolysis of 1- naphthyl chloroformate (1-NaphOCOCl) and 2-naphthyl chloroformate (2-NaphOCOCl) in pure and binary solvents have been measured at 2.0℃ and 10.0℃ using the conductometric method, respectively. From the kinetic data obtained, the specific rates of reaction were determined applying the simple and extended Grunwald-Winstein equations. The solvolysis of 1-NaphOCOCl can be well correlated (R = 0.934) with sensitivities toward changes in solvent nucleophilicity (l) of 1.59±0.15 and toward changes in solvent ionizing power (m) of 0.40±0.05, respectively. The solvolysis of 2-NaphOCOCl can be well correlated (R = 0.942) with sensitivities toward changes in solvent nucleophilicity (l) of 1.60±0.14 and toward changes in solvent ionizing power (m) of 0.45±0.05, respectively. In addition, the values of activation enthalpy and entropy were determined from the rate constants measured at various temperatures and activation entropies show large negative values. The solvent deuterium isotope effect [(kMeOH/kMeOD)1-NaphOCOCl = 2.49±0.02, (kMeOH/kMeOD)2-NaphOCOCl = 2.43±0.02] was considered for solvolysis in 100% MeOH and 100% MeOD. In conclusion, the solvolyses of 1-NaphOCOCl and 2-NaphOCOCl are indicated to proceed by bimolecular addition-elimination pathway over the full range of solvents.