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Theoretical DFT and experimental NMR studies on uracil and 5-fluorouracil

2002; Elsevier BV; Volume: 613; Issue: 1-3 Linguagem: Inglês

10.1016/s0022-2860(02)00171-0

1872-8014

B. Blicharska, Teobald Kupka,

Crystallography and molecular interactions

The results of extended MO calculations using density functional theory (DFT) approximation and multinuclear HR NMR studies on uracil (U) and 5-fluorouracil (5FU) are reported. The performance of the B3PW91 hybrid density functional was compared with the ab initio restricted Hartree–Fock (RHF) method. With the basis set 6-31G∗, or better quality, the DFT calculated bond lengths, dipole moments and harmonic stretching vibrations were predicted in good agreement with available experimental data. Structure and harmonic vibrations of U and 5FU were also calculated in the presence of water within a simple Onsager model. A linear correlation between proton and carbon GIAO NMR shieldings of uracil and 5FU and experimental data was shown.