6533b872fe1ef96bd12d3ae6

RESEARCH PRODUCT

Factors Governing the Chemical Stability and NMR Parameters of Uracil Tautomers and Its 5-Halogen Derivatives

Aneta BuczekKacper RzepielaMałgorzata A. BrodaTeobald Kupka

subject

Models MolecularMagnetic Resonance SpectroscopyNICSsolvent stabilizationMolecular ConformationPharmaceutical SciencePolarizable continuum modelDFTArticleAnalytical Chemistrylcsh:QD241-441tautomersHalogenslcsh:Organic chemistryComputational chemistryDrug DiscoveryHOMAPhysical and Theoretical ChemistryUracilDensity Functional TheoryBasis setMolecular Structure5-halogenouracil (5XU)ChemistryChemical shiftOrganic ChemistryAromaticityaromaticityTautomerChemistry (miscellaneous)Intramolecular forceSolventsMolecular MedicineChemical stabilityDensity functional theory

description

We report on the density functional theory (DFT) modelling of structural, energetic and NMR parameters of uracil and its derivatives (5-halogenouracil (5XU), X = F, Cl, Br and I) in vacuum and in water using the polarizable continuum model (PCM) and the solvent model density (SMD) approach. On the basis of the obtained results, we conclude that the intramolecular electrostatic interactions are the main factors governing the stability of the six tautomeric forms of uracil and 5XU. Two indices of aromaticity, the harmonic oscillator model of aromaticity (HOMA), satisfying the geometric criterion, and the nuclear independent chemical shift (NICS), were applied to evaluate the aromaticity of uracil and its derivatives in the gas phase and water. The values of these parameters showed that the most stable tautomer is the least aromatic. A good performance of newly designed xOPBE density functional in combination with both large aug-cc-pVQZ and small STO(1M)&minus

yearjournalcountryeditionlanguage
2020-08-01Molecules
10.3390/molecules25173931http://europepmc.org/articles/PMC7504704