Discipline: Chemistry and Chemical Sciences
Subcategory: Pollution/Toxic Substances/Waste
Shawnta D. Woods - Jackson State University
Co-Author(s): Wojciech Kolodziejczyk and Glake A. Hill, Jr., Jackson State University, Jackson, MS
Polycyclic Aromatic Hydrocarbons (PAHs) are pollutant compounds found in our environment caused by the partial combustion of organic materials during natural and human activities. PAHs are generally known to be very neutral, nonpolar molecules. They are moderately low in solubility when placed in water, but tend to be relatively high lipophilically. Most PAHs, with minimal vapor pressure, are adsorbed throughout the air onto particles. Once adsorbed, PAHs experience photodecomposition when ultra-violet (UV) light exposure is shone through solar radiation. These interactions produce diol epoxides, DNA adducts, and PAH quinones, which in turn create reactive oxygen species (ROS). The production of these products have been seen to have damaging effects within the human body, many of which cause cancer and other toxic mutations. Functioning with the notion to obtain insight into the excitation properties of the time-dependent density functional theory (TDDFT), we utilize an assortment of functionals to analyze the orbital- and density-based features (Natural Transition Orbitals (NTO) and charge density difference) of selected molecule; methyl substituted benz[a]anthracene. During excitation with light, electrons within the UVA range move from HOMO-1 to LUMO and from HOMO to LUMO+1. Double excitations are seen for methylated benz[a]anthracene in positions not previously recorded. We are able to conclude that HOMO-LUMO gaps are not good indicators for defining excitations for methylated benz[a]anthracene because of the double excitation retrieved.
References: Baum, E. 1978. In Polycyclic Aromatic Hydrocarbons and Cancer Edited by: Gelboin, H. and Ts’O, T. Vol. 1, 45-70. New York: Academic Press. Connell, D.W., Hawker, D.W., Warne, M.J. and Vowles, P.P. 1997. In Introduction into Environmental Chemistry Edited by: McCombs, K. and Starkweather, A.W. 205-217. Boca Raton, FL: CRC Press LLC. Srogi, K. 2007, Environ Chem Lett , 5:169-195Not Submitted
Funder Acknowledgement(s): I would like to thank the funder EPSCoR: 362492-190200-01NSFEPS-0903787. I would also like to thank the funder NSF CREST HRD-0833178.
Faculty Advisor: Glake A. Hill, Jr., firstname.lastname@example.org