Simulation of a tetramer form of 5-iodouracil: The vibrational spectra and molecular structure in the isolated and in the solid state by using DFT calculations

FTIR, FT-Raman, UV–Visible spectra and quantum chemical calculations of allantoin molecule and its hydrogen bonded dimers

“…The NAH out of plane bending vibrations are observed below the 580 cm À1 in the present vibrational spectra. The experimental wavenumbers corresponding to these vibrations are in well agreement with calculated anharmonic wavenumbers and are in accordance with literature [13,66,74].…”

Molecular structure and vibrational spectra of 2-thiouracil: A comparison with uracil

“…The band predicted at 1626 cm -1 in uracil and at 1622 cm -1 in 2-TU is assigned to ν(C=C) mode. All these assignments find wide support from literature values in related molecules [22][23][24][25][26][27][28][29][30][31][32][33][34].…”

Simulation of a tetramer form of 5-chlorouracil: The vibrational spectra and molecular structure in the isolated and in the solid state by using DFT calculations

“…In the isolated state, the m(C2@O) band position is predicted to remain almost unaffected by changes in the molecular structure under C-5 substitution [7][8][9][10][11][12][13]. As the halogen mass is increased, the corresponding m(C4@O) harmonic mode drifts slightly toward lower values.…”

“…Because of this importance, we have carried out a previous spectroscopic study on the single 5-fluorouracil molecule [6] as well as other 5-XU derivatives [7][8][9][10][11][12][13].…”