ja6b08714_si_001.pdf (3.48 MB)
An Isolable Bismabenzene: Synthesis, Structure, and Reactivity
journal contribution
posted on 2016-09-21, 00:00 authored by Takuya Ishii, Katsunori Suzuki, Taichi Nakamura, Makoto YamashitaA stable bismabenzene
was synthesized, isolated, and structurally
characterized. The prospective aromaticity of this heavy benzene,
bearing a sixth-row element, was examined by X-ray crystallography
and NMR and UV–vis spectroscopy, as well as theoretical DFT
calculations. Structural analysis of this bismabenzene revealed
a planar ring containing unsaturated Bi–C and C–C bonds.
As bond alternations could not be observed, these results are consistent
with the formal criteria of aromaticity. Theoretical calculations
also support the aromatic nature of this bismabenzene, which
reacted with an alkyne to form the corresponding [4+2] cycloadduct,
thus demonstrating a small yet tangible aromatic stabilization energy.