A theoretical and experimental investigation of the electronic spectra and tautomerization of nucleobases

摘要: The electronic structures of all possible tautomers uracil, thymine, cytosine, adenine and guanine have been carefully examined within the MNDO-MO frame-work. Equilibrium geometries are determined relative stabilities discussed. Allowance for solvent effect on is made by assuming a tetrahedral cage with DNA base occupying its centre. absorption spectra studied bases, in solvents different polarities recorded Assignments observed bands facilitated using MNDO-CI computations. It suggested that solution bases some statistical mixtures most stable tautomers, Watson-Crick (WC) structure cannot account alone.