Are Polarized Cyclobutadienes Non-Aromatic?
Mathias Ugelstad Frederiksen, Richard Francis Langler, Keith Jeffery Watson, Andrea Penwell and Katherine Valenta Darvesh
Australian Journal of Chemistry
53(6) 443 - 449
Published: 2000
Abstract
A series of non-alternant cyclobutadienes, both hydrocarbon and heteroatom-substituted, are examined by means of PM3 semiempirical molecular orbital calculations. The results show that even very substantial polarization has no simply predictable effect on antiaromatic character as measured by the singlet–triplet energy gap. MP2 calculations on selected hydrocarbons lead to the same conclusion.Keywords: Antiaromatic; non-alternant cyclobutadienes; MP2 computations; PM3 calculations; ground-state multiplicity.
https://doi.org/10.1071/CH99158
© CSIRO 2000
