FT-IR, FT-Raman, NMR spectra, and molecular structure investigation of C-۶ fluoroalkylated pyrimidine: A combined experimental and theoretical study

The FTIR and FT Raman spectra of C-۶ fluoroalkylated pyrimidine were recorded in the regions ۴۰۰۰–۴۰۰ and ۳۵۰۰–۱۰۰ cm–۱, respectively. The optimized geometry, wavenumber, and several thermodynamic properties of title compound were studied using ab initio Hartree–Fock and DFT methods with basis set ۶-۳۱G**. A complete vibrational assignment aided by the theoretical harmonic wavenumber analysis was proposed. The calculated harmonic vibrational frequencies were compared with experimental FTIR and FT Raman spectra. Based on the comparison between calculated and experimental results and the comparison with related molecules, assignments of fundamental vibrational modes were made. The X-ray geometry and experimental frequencies were compared with the results of theoretical calculations. For geometric data, good agreement between theory and experiment is obtained for the HF and B۳LYP levels. In addition, ۱H- and ۱۳C-nuclear magnetic shielding constants of this compound were calculated by employing the direct implementation of the gauge including-atomic-orbital (GIAO) method at the Hartree–Fock (HF) and DFT using ۶-۳۱G** basis set.

کلیدواژه ها:

C-۶ fluoroalkylated pyrimidin ، Optimized geometry ، Hartree–Fock ، Harmonic vibrational frequencies