The Excited State Dynamic Study Of Hetero-cyclic Aromatic Ketone By Resonance Raman Spectra And Density Functional Theory Calculation

Photo-induced electron transfer,hydrogen transfer and energy transfer reactions of aromaticcarbonyl compounds play an important role in chemical, biological and meterials science. In thispaper, the dynamic of1ππ*about4(3H)-Pyrimidone and3(2H)-Pyridazone that are soluted inacetonitrile and water is studied by Resonance Raman and Density Functional Theory study. Westudied the initial Excited-state structural dynamics and solvent effect, and the result as follows:(1). The UV spectra of4(3H)-Pyrimidone in different solvents, the FT-Raman spectroscopy andFT-IR spectroscopy of4(3H)-Pyrimidone, the Resonance Raman spectroscopy of4(3H)-Pyrimidonein different solvents at different excited wavelength are obtained. We obtained the ground stategeometric form and vibrational spectroscopy by DFT. The electron absorption spectroscopy in gasphase and solvent mode are calculated by TD-DFT. The vibrational assignments are done for4(3H)-Pyrimidone.(2). The data of3(2H)-Pyridazone are done using the same method, and the vibrationalassignments are done.(3).The viriation trend of dynamic reaction coordinate of4(3H)-Pyrimidone in Franck-Condonregions which is along the C=O stretch and C-H bend is controlled by the polarity of solvent andexcited wavelength. The Franck-Condon regions excited state short-time structural dynamics of4(3H)-Pyrimidone in nonpolary solvent proceeds along the C=O stretch and keeps active. TheFranck-Condon regions excited state short-time structural dynamics of3(2H)-Pyridazone is tunedalong the C=O stretch when the solvent goes from water to acetonitrile solvent. There is difference indynamic structure that there is a combination tone in base tone regions of4(3H)-Pyrimidone inA-band Resonance Raman, and it is possible that it promotes proton-transfer process.The study of4(3H)-Pyrimidone and3(2H)-Pyridazone reveals the the initial Excited-statestructural dynamics is internal-molecular proton transfer in Franck-Condon regions.