Theoretical and spectroscopic study of infrared spectra of hydrogen-bonded 1-methyluracil crystal and its deuterated derivative.
Theoretical simulation of the band shape and fine structure of the N-H(D) stretching band is presented for 1-methyluracil and its deuterated derivative taking into account anharmonic coupling between the high-frequency N-H(D) stretching and the low-frequency N...O stretching vibrations, resonance interaction between two equivalent hydrogen bonds in the dimer, anharmonicity of the potentials for the low-frequency vibrations in the ground and excited state of the N-H(D) stretching mode, Fermi resonance between the N-H(D) stretching and the first overtone of the N-H(D) bending vibrations, and electrical anharmonicity. The effect of deuteration has been successfully reproduced by our model calculations. Infrared, far-infrared, Raman, and low-frequency Raman spectra of the polycrystalline 1-methyluracil have been recorded. The geometry and experimental frequencies are compared with the results of harmonic and anharmonic B3LYP6-311++G(**) calculations.
Boczar
Marek
M
Faculty of Chemistry, Jagiellonian University, 30-060 Kraków, Ingardena 3, Poland.
Kwiendacz
Jacek
J
Wójcik
Marek J
MJ
D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D003903:Deuterium / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D008958:Models, Molecular; D013055:Spectrophotometry, Infrared / Q000379:methods*; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry
D014498:Uracil; C002596:1-methyluracil; D006859:Hydrogen; D003903:Deuterium