Substituted tetraphenylethylenes: Computational studies and efforts toward synthesis for the investigation of the captodative effect

CHED 317

Andrew M. Handorf, Katherine J. Eannelli, and Louise L. Stracener, lstracener@edgewood.edu. Department of Natural Science, Edgewood College, 1000 Edgewood College Drive, Madison, WI 53711
Several substituted tetraphenylethylenes have been investigated computationally using density functional theory and other methods. The dependence of the geometries of these compounds, specifically the phenyl torsional and olefin twist angles, on the methyl substitution patterns have been explored. In addition, the effects of electron-donating and -withdrawing para substituents on the geometries and the cis-trans isomerization barriers of these tetraphenylethylenes have been investigated in order to determine a.) whether any captodative stabilization of the biradical transition state exists, and b.) whether any synergistic stabilization is affected by the phenyl torsional angle. A synthetic scheme for these derivatives has also been proposed, and efforts to synthesize these derivatives in order to probe the cis-trans isomerization experimentally are ongoing.