DFT simulations and vibrational analysis of FTIR and FT‐Raman spectra of 2‐amino‐4,6‐dihydroxypyrimidine

Abstract

This work deals with the vibrational spectroscopy of 2-amino-4,6-dihydroxy pyrimidine (ADHP) by means of quantum chemical calculations. The mid-and far FTIR and FT-Raman spectra were measured in the condensed state. The fundamental vibrational wavenumbers and intensity of vibrational bands were evaluated using density functional theory (DFT) with the standard B3LYP/6-311+G * * methods and basis set combinations, and were scaled using various scale factors, which yielded good agreement between the observed and calculated wavenumbers. The vibrational spectra were interpreted with the aid of normal coordinate analysis based on the scaled density functional force field. The results of the calculations were applied to simulate the infrared and Raman spectra of the title compound, which showed excellent agreement with the observed spectra.

Quantum chemical calculations on elucidation of molecular structure and spectroscopic insights on 2-amino-4-methoxy-6-methylpyrimidine and 2-amino-5-bromo-6-methyl-4-pyrimidinol – A comparative study

“…For ABMP, the computed scissoring vibration is predicted at 1642 cm -1 which is in excellent agreement with the experimental value in FTIR spectrum at 1643 cm -1 . This is also supported by the literature data [34][35][36].…”

Computational prediction of vibrational spectra of normal and modified DNA nucleobases

“…[110] Using the B3LYP functional and 6-31+Gd and 6-311+G(d,p) basis sets, they have predicted the total energies of the different conformers of the molecule and identified the most stable conformer (Fig. 2).…”

“…a UVRR wavenumber from Wen and Thomas. [59] Guanine [52,56] Raman 1675 w --1602vw 1542 m 879vw 603vw 649 vs Guanosine [58,59] UVRR 1685 w --1643 w 1575 m 670 w GMP [60] UVRR 1681 w --1602 m 1576 m 671vw 8-oxodG [60] UVRR 1677vw -1715 w 1610s 1601s 1455 m 1445 m -IR 1681 vs -1705s 1594 vs -605vw 7-Allyl-8-oxodG [60] UVRR 1674 w -1706 m 1605 vs 1455 m 1433 m 613vw IR 1676 vs -1704 vs 1596s 611 w Xanthine [92] IR 1658 1700 vs --1567 ms 538s Raman 1600 ms 1685 ms --1560s 547 ms Hypoxanthine [74,77] Raman 1691m ---735 vs Inosine [80] UVRR 1688 ---2 -Deoxyinosine [85] IR 1719s ---1592vw 843 w 719vw 725vw,sh Raman 1689 m ---1591vw 842 vs 719 vs 724 vs IMP [116] UVRR 1684 w ---1462 w 724 m Allopurinol [78,79] IR 1701s ---1434 w -536m Raman 1696 m ---719 vs Caffeine [87,92] IR [51] UVRR 1652 m 1605 w -782 vs anionic HO 5 dCyt [15] UVRR 1628 m 1615 m -1-Methylcytosine [118] Raman 1648 w -777 vs 5-Methylcytosine [118] Raman 1655 m 1,5-Dimethylcytosine [118] Raman 1665 w -Flucytosine [112] IR 1683 vs, 1671 vs 1651ov 898 m Raman 1679 m 1646 w 901 w 4-Aminopyrimidine [109] IR -1611 w 1584 817 w -988s ADHP [110] IR 1698s 840 m -DAHNP [111] Raman -1693 w, 1664vw --Coupled mode is given in bold face. ν, stretching; γ , out of plane bending; bre, breath; vs, very strong; s, strong; m, medium; w, weak; vw, very weak; sh, shoulder; ov, overlapped.…”

Structures and internal dynamics of diphenylether and its aggregates with water

“…O and DPE-(H 2 O) 2 , the harmonic frequency calculations were combined with calculated Raman activities (performed with Gaussian 09) 61. These calculated Raman activities were converted to Raman intensities by the formula adapted by the work of Polavarapu and Prabavathi65,66 (cf. ESI).…”