Hydrolysis of Sulfamoyl Chlorides. II. Hydrogen Participation in the Hydrolysis of Diethyl and Methylethylsulfamoyl Chlorides

Autor: R. E. Robertson, E. C. F. Ko
Rok vydání: 1972
Předmět:
Zdroj: Canadian Journal of Chemistry. 50:946-951
ISSN: 1480-3291
0008-4042
DOI: 10.1139/v72-146
Popis: Diethylsulfamoyl chloride (2) hydrolyzes eight times faster than dimethylsulfamoyl chloride (1). In 2 the secondary deuterium isotope effect was found to be about 2, hence hydrogen participation is important in the hydrolysis of this compound. The temperature coefficient of the enthalpy of activation [Formula: see text] is exceptional (−39 cal mol−1 deg−1) for a reaction presumably following an SN1 mechanism. The kinetic solvent isotope effect was normal for such a mechanism. The corresponding value of [Formula: see text] for the hydrolysis of piperidylsulfamoyl chloride (4) was about the same as found for 2 while the value for the methylethyl isomer (3) was −66 cal deg−1 mol−1, an intermediate value supporting an explanation based on solvent exclusion. Experiments in mixed solvents support the hypothesis that solvent reorganization is the major factor in determining the value of [Formula: see text]for 2 but not for 4.
Databáze: OpenAIRE