2. *The ring-closure process occurs on fast timescales <1 ps
*The ring-opening is a slower reaction on the timescale of several picoseconds
*The ring-opening reaction also proved to be sensitive to solvent effects, the environment temperature and
the specific excitation wavelength.
3.
4. *Dihydroazulenes (DHA) open photochemically to form the thermally unstable vinylheptafulvenes
(VHF).
*The switching of VHF to DHA is thermally assisted.
*VHF and DHA exhibit different absorption spectra in the UV-vis. region.
*The activation barrier for thermal return of VHF to DHA (in neutral state) is reported as 28.04 kcal
mol-1
The ring-opening reaction (DHA-VHF) occurs with a high quantum yield
