Electron Propagator Theory of Guanine and Its Cations: Tautomerism and Photoelectron Spectra

摘要: Electron propagator methods are applied to the ionization energies of five most stable tautomers guanine. Excellent agreement with gas-phase photoelectron spectra is obtained for amino-oxo form 7H-guanine. According energy assignments, both 9H-guanine and its amino-oxy also may be present in gas phase. The presence 7H-guanine, however, less certain, due higher total energy. In all cases, lowest occurs from a π level. There strong correlation effects cationic states. Energy orderings σ hole states different each isomers.