N-K spectra of adenine amino tautomers

摘要: Adenine tautomeric process is not a small perturbation but significant change of the inner shell configuration. For canonical adenine, ade n9, inner-shell configuration in ground electronic states (X1A') given by 1a'(N(9))2a'(N(10))3a'(N(7))4a'(N(3))5a'(N(1)) 6a'(C(6))7a'(C(8))8a'(C(4))9a'(C(2))10a'(C(5)). Although five N1s orbitals core all adenine amino tautomers are always as 1a'2a'3a'4a'5a'. The profound tautomer dependent reconfiguration has been largely masked net differences their total energies and subtle valence structures. present quantum mechanical spectral study demonstrates that chemical shift atomic site specific: orbital binding energy shifts sites (-N-) smaller than those imino (-N=) same tautomer. nitrogen N@1s (an site) which connects mobile hydrogen exhibits smallest within therefore, an indicator specific preferential (ade n9) protonation order 5a'(N(1)), 4a'(N(3)) 3a'(N(7)) agrees with previous observations.