- The high temperature conditions can be created
by photoirradiation. The highly vibrationally excited state,
namely a hot molecule, which has an equivalent vibrational temperature
of 2000-4000 K, would be produced after a rapid internal conversion
from an electronically excited state. The hot molecules are known
to be formed by the VUV-UV laser irradiation of gaseous molecules.
However, studies of the hot molecule reactions using lasers were
limited to a small variety of molecules. The molecules other
than aromatic hydrocarbons and olefins have not been well studied.
The large molecules such as aromatic hydrocarbons larger than
naphthalene have also not been well studied because they did
not have a sufficient vapor pressure at ambient temperature.
We have reported the hot molecule chemistry of large molecules
such as naphthalene and 2, 2-paracyclophane.The large molecules,
which have a low vapor pressure at room temperature, could be
used for the experiments by elevating the experimental temperature
for efficient vaporization and for enough absorbance at the laser
wavelength. In the case of 2,2-paracyclophane, the experiments
were carried out at 453 K. In these cases, product formations
by the two-photon process were observed.