A Strong cis-Effect in an Imidazole-Imidazolium-Substituted Alkene.
Dayne C GeorgiouMohammad A HaghighatbinConor F HoganMichael S ScholzJames N BullEvan J BieskeDavid J D WilsonJason L DuttonPublished in: Angewandte Chemie (International ed. in English) (2017)
We report the first example of an alkene with two carbon-bound substituents (imidazole and imidazolium rings) where the Z-isomer has a greater thermodynamic stability than the E-isomer which persists in both the gas phase and in solution. Theoretical calculations, solution fluorescence spectroscopy and gas-phase ion mobility mass spectrometry studies confirm the preference for the Z-isomer, the stability of which is traced to a non-covalent interaction between the imidazole lone pair and the imidazolium ring.