Beilstein Journal of Organic Chemistry (Jul 2019)

Cyclobutane dication, (CH2)42+: a model for a two-electron four-center (2e-4c) Woodward–Hoffmann frozen transition state

  • G. K. Surya Prakash,
  • Golam Rasul

DOI
https://doi.org/10.3762/bjoc.15.148
Journal volume & issue
Vol. 15, no. 1
pp. 1475 – 1479

Abstract

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The structures of the elusive cyclobutane dication, (CH2)42+, were investigated at the MP2/cc-pVTZ and CCSD(T)/cc-pVTZ levels. Calculations show that the two-electron four-center (2e-4c) bonded structure 1 involving four carbon atoms is a minimum. The structure contains formally two tetracoordinate and two pentacoordinate carbons. The non-classical σ-delocalized structure can be considered as a prototype for a 2e-4c Woodward–Hoffmann frozen transition state. The planar rectangular shaped structure 2 with a 2e-4c bond was found not to be a minimum.

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