This RUI grant from the Organic Dynamics Program supports the continuing work of Professor Cheryl Stevenson at Illinois State University to study anions and anion radicals of annulene and homoannulenes. These NMR and EPR spectroscopic studies will make use of deuterium isotopic perturbation techniques. The four focal point of research are the determination of equilibria between ring-opened and ring-closed 16 annulene structures, the characterization of the electron distribution in sigma-bonded 16 - 8 - and 16 - 6 -bisannulenes, the analysis of the deuterium effect on the splitting of the degeneracy of non-bonding orbitals of 8 - and 16 -annulenes, and the isotope effect of the solution electron affinity of pyrene. In this project Dr. Stevenson will conduct spectroscopic studies on dianions and anion radicals of differently sized annulenes. Her undergraduate research employs the deuterium isotopic perturbation technique to investigate their bonding properties and electronic distributions. The fundamental studies on the isotope effect on orbital splitting and solution electron affinities will be supported by collaborative theoretical studies.