Chlorine Isotope Effects in the Reactions of Benzyl and Substituted Benzyl Chlorides with Various Nucleophiles

Journal Article · Sun Jul 01 04:00:00 UTC 1962 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00873a025· OSTI ID:4816896

Hill, John W.; Fry, Arthur.

The kinetics and chlorine isotope effects in the nucleophilic substitution reactions of benzyl and substituted benzyl chlorides with water, cyanide ion, and thiosulfate ion were investigated. For those reactions exhibiting first-order kinetics, the kinetic isotope effect (k³⁵//k³⁷ ) observed was close to 1.0078, while for reactions displaying second-order kinetics the value was 1.0058. Those reactions proceeding by borderline kinetics gave isotope effects intermediate between these two extremes. Detailed analysis of the kinetic and isotope effect data for the reactions with cyanide and thiosulfate ions led to the conclusion that there is a smooth transition in the reaction mechanism from near ideal SN 1 to near ideal SN 2 as the electrondonating power of the substituent decreases. It appeared that the magnitude of the chlorine isotope effect may be used to differentiate between SN 1 and SN 2 reactions.

• Research Organization: Univ. of Arkansas, Fayetteville
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-025344
• OSTI ID: 4816896
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 14 Vol. 84; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
CHLORINE
CHLORINE 35
CHLORINE 37
CYANIDES
ELECTRONS
ISOTOPE EFFECTS
ORGANIC CHLORINE COMPOUNDS
REACTION KINETICS
SULFATES
WATER