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

6-Aminouracil: Geometries and spectra in the isolated state and in the solid state simulation. A comparison with 5-aminouracil

“…The experimental bands reported at 430 [25], 416 [26] and 450, 430 [27] cm À1 were reassigned to this inplane bending mode, instead of its assignment by these authors and 734 (Raman) cm À1 , and it was related to the experimental band at 764 cm À1 in IR and 768 cm À1 in Raman. This assignment finds also support with that reported experimentally in uracil molecule at 769 cm À1 [51], in 5-chlorouracil at 743 (IR) and 740 cm À1 (Raman) [66], in 6-chlorouracil at 758 (IR) and 723.3 cm À1 (Raman) [58], and in 5-fluorouracil at 740 cm À1 (IR) [67]. However, the other authors have assigned the IR band at 630 cm À1 [25], 644 cm À1 [26], Table 4 Calculated harmonic wavenumbers (u, cm À1 ), relative infrared intensities (A, %), relative Raman intensities (S, %), Raman depolarization rations for plane (P) and unpolarized (U) incident light and force constants (f, mDyne/Å) obtained in the NH 2 amino group of the monomer form of 6-aminoU at different levels of computation, together with the scaled values (n, cm À1 ).…”

“…This mode is scaled at 430 (IR) and 404 (Raman) cm À1 , in the tetramer form in agreement with the experimental strong IR band at 443 cm À1 and with the Raman band with weak intensity observed at 421 cm À1 . This assignment finds further support from that reported experimentally in 5-aminoU at 418 cm À1 (IR) and 418.9 cm À1 (Raman) [62], in 5-chlorouracil at 446 cm À1 (IR) and 457 cm À1 (R) [66], in 6-chlorouracil at 451 cm À1 (IR) and 443 cm À1 (R) [12], and in 5-fluorouracil at 419 cm À1 (IR) and 413 cm À1 (R) [65]. The experimental bands reported at 430 [25], 416 [26] and 450, 430 [27] cm À1 were reassigned to this inplane bending mode, instead of its assignment by these authors and 734 (Raman) cm À1 , and it was related to the experimental band at 764 cm À1 in IR and 768 cm À1 in Raman.…”

“…The n(N1eH) stretching vibration (mode 30 following to the uracil ring notation [51]) is predicted at higher values than n(N3eH) vibration (mode 29), in accordance to that reported in other derivatives of uracil [62,64,66]. In the isolated state, the IR intensity is calculated to be the same in both N1eH and N3eH groups.…”

The effect of water-mediated catalysis on the intramolecular proton-transfer reactions of the isomers of 5-chlorouracil: a theoretical study

“…Furthermore, 5ClU can be used in the synthesis of drugs in anticancer therapy as it has good anti-inflammatory and antineoplastic activities (Henderson et al, 2003b;Jiang et al, 2003). It was also found that this molecule has antitumour activity in some nickel (II) and cobalt(II) metal-ion complexes (Singh et al, 1988(Singh et al, , 1989Narang et al, 1998;Ortiz et al, 2013).…”

Synthesis and Structural Studies of Three Uracil Derivatives, Methyl 3-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)propanate, Methyl 3-(5-Nitro-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)propanoate and Ethyl 3-(5-Nitro-2,4-dioxo-3,4-dihydropyrimidin-1 (2H)-yl)propanoate

“…It is one of the first molecules studied by crystal structure prediction, the results of which have revealed a wide range of different, plausible hydrogen bonding motif within a small energy range [3,4]. The vibrational studies on uracil and 5-substituted uracils have also been made by several researchers, which regarded be helpful in understanding their scientific vibrational results with the view of biological process and in the analysis of relatively complex systems [5][6][7][8][9][10][11][12]. Moreover, the biological activity of uracil and its derivatives has stimulated exceptional interest in biochemistry and pharmacology [13][14][15][16][17][18].…”