Diverse mixtures of 2,4-dihydroxy tautomers and O4 protonated conformers of uridine and 2'-deoxyuridine coexist in the gas phase.

Diverse mixtures of 2,4-dihydroxy tautomers and O4 protonated conformers of uridine and 20-deoxyuridine coexist in the gas phase†

Tautomerization lowers the activation barriers for N-glycosidic bond cleavage of protonated uridine and 2'-deoxyuridine.

The gas-phase conformations of protonated uridine, [Urd+H](+), and its 2'-deoxy form, protonated 2'-deoxyuridine, [dUrd+H](+), have been examined in detail previously by infrared multiple photon dissociation action spectroscopy techniques. Both 2,4-dihydroxy tautomers and O4 protonated conformers of [Urd+H](+) and [dUrd+H](+) were found to coexist in the experiments with the 2,4-dihydroxy tauto...

Structural Investigation, Proton and Electron Affinities, Gas Phase Basicities, and Ionization Energies of Captopril

Captopril is one of the most significant angiotensin-converting enzyme inhibitors. In spite of numerous experimental and computational studies on its properties, not enough geometrical and thermodynamic data is available on this compound. So, this study aimed to investigate the structural properties and assignment of possible conformers of captopril in the gas-phase. To this end, 1152 unique tr...

A Theoretical Study on the Aromaticity of 5-methylcytosine tautomers in the gas phase

The armaticity of 5 methylcytosine tautomers in the gas phase has been studied and the chemical structures of related tautomers are investigated . The electronic energy, enthalpy and free energy of each tautomer are also estimated at the B3LYP/6-31 G* // B3LYP/6-31 G* and MP2 / 6-31 G* // MP2 / 6-31 G* Levels

The thermochemistry of 2,4-pentanedione revisited: observance of a nonzero enthalpy of mixing between tautomers and its effects on enthalpies of formation.

The enthalpies of formation of pure liquid and gas-phase (Z)-4-hydroxy-3-penten-2-one and 2,4-pentanedione are examined in the light of some more recent NMR studies on the enthalpy differences between gas-phase enthalpies of the two tautomers. Correlation gas chromatography experiments are used to evaluate the vaporization enthalpies of the pure tautomers. Values of (51.2 +/- 2.2) and (50.8 +/-...