Yost, Shane R.Larson, Christopher Michael2020-07-212020-07-212020-05Larson, C. M. (2020). Assessment of chemical modifications on the photophysical properties and stability of isoindole moieties (Unpublished thesis). Texas State University, San Marcos, Texas.https://hdl.handle.net/10877/12134Isoindoles are used in biochemical and biomedical applications for drug delivery as medication releasing agents.However, they are not stable in biological conditions. Different isoindole derivatives were theoretically created typically with structural changes via addition of functional groups to the stationary isoindole structure. These derivatives were analyzed via computational software using the time-independent, linear response form of Time Dependent Density Functional Theory (TDDFT). The absorption and emission energies were characterized for each molecule, as well as bond distances, partial charges and valence electron states. Small chemical modifications were found to produce significant changes in the properties of these molecules, some of which show increased stability. Of the 11 moieties, molecules 9 and 11 show significant deviations in the Stokes shift from the skeleton molecule, molecule 1. No real correlation was found between the R3side group carbon-hydrogen distance and the Mulliken partial charge on the carbon. Attachment and detachment plots displayed molecule 11 is in a charge-transfer state and not favored. Molecules 1, 4 and 9 attachment and detachment plots exhibit a valence-excited state. Molecules 4, 5, 8, and 10 had energy differences between the 1H-Isoindole and 2H-Isoindole that resemble increased stability, where molecules 7 and 9 displayed lower energy differences and lower stability.Text29 pages1 file (.pdf)en2H-Isoindolestokes shiftHonors College