The Influence of a Terminal Chlorine Substituent on the Kinetics and the Mechanism of the Solvolyses of n -Alkyl Chloroformates in Hydroxylic Solvents

• Published in: International journal of molecular sciences Vol. 21; no. 12; p. 4387
• Main Authors: D'Souza, Malcolm J, Wirick, Jeremy, Mahmoud, Osama, Kevill, Dennis N, Kyong, Jin Burm
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.06.2020; MDPI
• Subjects: 3-chloropropyl chloroformate; 4-chlorobutyl chloroformate; butyl chloroformate; Chloride; Chlorine; Chlorine - chemistry; Chloroformate; Ethanol; Formates - chemistry; Grunwald–Winstein equation; Hydroxyl Radical - chemistry; Ionization; Kinetics; Molecular Structure; propyl chloroformate; Solvents; Solvents - chemistry; Solvolysis; Studies; butyl chloroformate; 4-chlorobutyl chloroformate; 3-chloropropyl chloroformate; Grunwald–Winstein equation; ionization; solvolysis; addition-elimination; propyl chloroformate
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21124387

A previous study of the effect of a 2-chloro substituent on the rates and the mechanisms of the solvolysis of ethyl chloroformate is extended to the effect of a 3-chloro substituent on the previously studied solvolysis of propyl chloroformate and to the effect of a 4-chloro substituent on the here reported rates of solvolysis of butyl chloroformate. In each comparison, the influence of the chloro substituent is shown to be nicely consistent with the proposal, largely based on the application of the extended Grunwald-Winstein equation, of an addition-elimination mechanism for solvolysis in the solvents of only modest solvent ionizing power, which changes over to an ionization mechanism for solvents of relatively high ionizing power and low nucleophilicity, such as aqueous fluoroalcohols with an appreciable fluoroalcohol content.