The first excited triplet state (TI state) of aromatic hydrocarbons such as phenanthrene acts as an intermediate in many chemical and photochemical reactions. The TI state is a metastable state and its lifetime can be measured in terms of its decay to the ground state. The duration of this decay is on the order of microseconds. Therefore, techniques for measuring the kinetics of fast reactions must be employed in the determination of the rate of the TI state decay, one such technique that is utilized in this research is flash photolysis. The rate of the Tl state decay is greatly enhanced by the presence of oxygen. Therefore, to accurately measure the first order Tl state decay, the phenanthrene solution must be degassed prior to flashing in order to remove dissolved oxygen. A vacuum line is designed for this purpose. Based on the experimental data, it was determined that scattered flash light must be eliminated from the flash apparatus and that the vacuum line must be redesigned for more efficient degassing
