Free-base corrole is a tetrapyrrolic organic compound with three meso methane carbon bridges, and one direct pyrrole-pyrrole connection. Corrole exist in two tautomeric forms, Tautomer 1 and Tautomer 2, and because the changes of the position of a single proton, the macrocycle adopt a different conformation. This difference in the tautomers causes them to exhibit different photophysical and electrochemical behavior in different solvents. A clear understanding of tautomers structural conformation and solvent dependence is necessary to develop their potential use in artificial photosynthetic devices and in cancer diagnosis and treatments. In our research group, we have investigated which solvent property controls the formation of either tautomer in free-base triphenylcorrole (H3TPCor). We have found that the ability of solvent molecules to do hydrogen bonding with H3TPCor will determine which tautomer will be formed. However, it still is poorly understood how and where the solvent molecules associate with the macrocycle and how these interactions affect the formation of the tautomers. We have performed calculations and molecular modeling analysis to identify possible sites where solvent molecules can interact with H3TPCor and to predict the formation of one tautomer against the other. The calculations were run in various solvents to obtained energy profiles by constraining the distance of the proton transferred between tautomers. We have also compare molecular orbital energies and electrostatic potential energy surfaces with several conformational properties of the macromolecule and the photophysical properties obtained in the lab.

Computational analysis of corrole tautomers in various solvents

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.