γ-dissociations of 3-alkylbicyclo[1.1.1]pent-1-yl radicals into [1.1.1]propellane and alkyl radicals: Verification of a theoretical prediction

John C. Walton*, Lewis Whitehead

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The γ-dissociations of 3-substituted bicyclo[1.1.1]pent-1-yl radicals and cyclobutyl radicals were investigated by ab initio SCF MO (HF, MP2, MP3 and MP4/6-31G*) and density functional methods (B3LYP/6-31G*). The transition states were found to resemble the product alkyl radical and [1.1.1]propellane or bicyclo[1.1.0]butane. Calculated endothermicities and energy barriers were comparatively low for loss of the t-butyl radical from the 3-t-butylbicyclo[1.1.1]pent-1-yl radical, which suggested that this dissociation would be significant under laboratory conditions. The dissociation was verified experimentally by means of the reaction of 1-iodo- 3-t-butylbicyclo[1.1.1]pentane with tributyltin hydride. Arrhenius parameters for this dissociation were determined by end product analysis. The SCF MO and density functional calculations resulted in much higher endothermicities and energy barriers for γ-dissociations of cyclobutyl radicals, hence neither the formation of bicyclo[1.1.0]butane nor alkyl radical addition to this bicyclic compound was predicted to be important.

Original languageEnglish
Pages (from-to)1399-1404
Number of pages6
JournalPhysical Chemistry Chemical Physics
Volume1
Issue number7
DOIs
Publication statusPublished - 1 Apr 1999

Fingerprint

Dive into the research topics of 'γ-dissociations of 3-alkylbicyclo[1.1.1]pent-1-yl radicals into [1.1.1]propellane and alkyl radicals: Verification of a theoretical prediction'. Together they form a unique fingerprint.

Cite this