The goal of this work is to understand the unimolecular reaction dynamics of the ground electronic states of small molecules and hence of their thermal unimolecular reactions. Three kinds of experiments will be conducted: 1) infrared spectroscopy of molecules activated with sufficient vibrational energy to dissociate, 2) direct measurement of dissociation rates in the range from 1 million to 100 billion per second, and 3) measurement of product energy state and angular momentum distributions and their scalar and vector correlations as a function of the initial quantum state of the activated molecule. Special emphasis will be given to two qualitatively different, prototype molecules- formyl fluoride and ketene. The dynamics of chemical reactions stands at the forefront of investigations in contemporary physical chemistry. The primary purpose of these investigations is to obtain a detailed, molecular level understanding of the energetics and dynamics of reaction processes. This involves the preparation of a molecule in defined electronic, vibrational, and rotational quantum states and observing not only the products of a reaction, but also how the total energy and angular momentum redistribute themselves among the various possible reaction channels followed by the parent molecule as it dissociates into fragments. In contrast to conventional methods in which chemical reactions can be only crudely controlled through variations of temperature and pressure, and in which all possible reaction channels are followed, a detailed, molecular level understanding of the reaction dynamics offers the possibility of close control of a reaction and thereby maximizing the efficiency of producing the desired reaction products. The present research will provide critical data which will allow the testing and further development of state-of-the-art theoretical models for various aspects of chemical reaction kinetics and dynamics.
