3 years ago

Quantum-chemical studies on the favored and rare isomers of isocytosine

Quantum-chemical studies on the favored and rare isomers of isocytosine
Quantum-chemical calculations have been performed for twenty-one favored and rare isomers of neutral isocytosine in two extreme media, in the gas phase {B3LYP/6-311+G(d,p)} and in aqueous solution {PCM(water)//B3LYP/6-311+G(d,p)}. In aqueous solution, the most aromatic hydroxy-amino form, favored in the gas phase, becomes a rare form, and less delocalized amino-oxo forms predominate. Monoprotonation of the favored isomers leads also to two different forms, the N1-protonated hydroxy-amino cation in the gas phase, and the N1-protonated amino-oxo cation in aqueous solution. Electron delocalization for the solvated isocytosine isomers is parallel to that observed for the isolated molecules. However, aromaticity is not the main factor that influences isomeric stabilities. Geometric and energetic results for neutral isocytosine isomers, compared to those for other pyrimidine bases (uracil and cytosine), show interesting similarities in electron delocalization and important differences in energetic stabilities. Some parallelism in energetic parameters exists for amine-imine and enamine-imine conversions, and separately for amide-iminol and keto-enol ones.

Publisher URL: www.sciencedirect.com/science

DOI: S2210271X17304450

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.