The energetic and medium requirements in chemical processes involving electron transfer will be probed with specially designed equipment. The systems of donor-acceptor pairs to be investigated will allow studies to be made of the relationship between exciplex emission and charge transfer emission, the relationship between energetics and rates of photoinduced electron transfer, and the role of proteins as the media in biological photoinduced electron transfer. One of the bichromophoric systems to be studied will have as the donor/acceptor pair a substituted anthracene and a dimethylaniline group which is separated by a spacer of varying length. The spacer will consist of methylene or amido units. Such a series of compounds will allow the energetics of these processes to be probed by changes in substituents and the geometry of the transfer processes to be probed by varying the length of the spacer. The studies will be carried out with a transient spectrometer and a supersonic jet to obtain high-resolution spectra. %%% This grant from the Organic Dynamics Program supports the research of Professor N. C. Yang at the University of Chicago. Factors that govern electron transfer between two groups within a molecule will be studied. One of the groups will be promoted to an excited state by the absorption of light energy. Subsequently, electron transfer from this excited group to the other electron acceptor group in the molecule can be studied by fast spectroscopic techinques. The energetics of the process will be probed by altering one of the groups with other substituents which facilitate or retard electron transfer. Electron transfer is of fundamental importance in the conversion of light into chemical energy in many biological processes including photosynthesis and thus this research will be of considerable interest to a wide range of scientists.
