In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Professor Baer will design and carry out experiments in the infrared region of the spectrum to measure the rates with which loosely bound clusters of atoms and ions come apart. The ultraviolet region of the spectrum will be used to probe the behavior of more complex organic compounds containing oxygen and nitrogen. The high resolution infrared spectroscopy and dissociation rates of loosely bound ionic clusters will be investigated by IR photodissociation of mass selected cluster beams. The ion lifetimes will be measured in real time. The Rydberg spectroscopy of oxygen and nitrogen containing ring compounds will be investigated by resonance enhanced multiphoton ionization to explore the origin of the spectral sensitivity to a molecule's stereochemistry.