Gas phase structures of the isomers of benzene,V. (dewar-benzene) by electron diffraction

The parent hydrocarbon, Dewar-benzene, has been studied by gas phase electron diffraction analysis. Assignment of C_2v symmetry gave excellent agreement between the experimental and theoretical data. The structural parameters obtained were in good agreement with previous electron diffraction structures of substituted derivatives of the Dewar-benzene series. The structural parameters with error limits are (cf. Fig. 2): r(C₃-C₆) = 1.574 ± 0.005 Å r(C₂-C₃) = 1.524 ± 0.002 Å, r(C₁-C₂) = 1.345 ± 0.001 Å, r(C₃-C₉) = 1.134 ± 0.004 Å, r(C₁-C₇) = 1.124 ± 0.004 Å, ∠C₁C₆C₅ = 116.7 ± 0.6°, ∠C₃C₆C₁ = 85.7 ± 0.2°, ∠C₆C₃C₉ = 108.0 ± 3.0°, ∠C₃C₂C₈ = 126.7 ± 2.5°, and α = 117.25 ± 0.6°. The angle γ was assumed to be 0°.