Synthesis and properties of butatrienes containing a bisdehydro[13]annulene system as terminal groups
作者:Masahiko Iyoda、Shigeyoshi Tanake、Kazuhiko Nishioka、Masaji Oda
DOI:10.1016/s0040-4039(00)88044-2
日期:1983.1
The compounds bearing a butatriene linkage between bisdehydro[13]annulene and electron donating and withdrawing systems have been synthesized. The contribution of a dipolar structure in these compounds is discussed on the basis of the spectral data.
We report visible color changes and new intense, bathochromically shifted bands in electronic absorption spectra that reach into the near-infrared region (up to 862 nm) upon protonation of nine pentafulvene and expanded pentafulvalene derivatives. This phenomenon can only be explained by the formation of carbocations with highly delocalized charges. Solution pKa values in organic solvents were determined