Infrared spectra of pyrazine, pyrimidine and pyridazine in solid argon

Abstract

The vibrational spectra of monomeric diazines (pyrazine, pyrimidine and pyridazine) isolated in solid argon and of the neat crystalline phase of these compounds, at 10 K, are reported and discussed. Full assignment of the spectra is presented, providing evidence that the assignments of several bands previously undertaken for the compounds under other experimental conditions (e.g., gas phase, neat liquid or solution) shall be reconsidered. The interpretation of the experimental data is supported by extensive DFT calculations performed with the B3LYP functional and the 6-311CCG(d,p) basis set and by comparison with the anharmonic vibrational calculations reported by Boese and Martin [

Syntheses, spectroscopic and thermal analyses of the hofmann-type metal(II) tetra- cyanonickelate(II) pyridazine complexes: {[M(pdz)Ni(CN)4]∙H2O}n (M = Zn(II) or Cd(II))

“…The vibrational spectra of Zn-Ni-pdz and Cd-Ni-pdz complexes are shown in Figures 1 and 2, respectively. The assignments and the wavenumbers of the vibrational bands of pdz observed in the spectra of the complexes studied are listed in Table 1, together with free pdz wavenumbers for comparison [9,18]. The absorption bands of the complexes are observed in the region from 3700 cm -1 to 3300 cm -1 because of symmetric and asymmetric (OH) stretching vibrations of the coordinated water molecules.…”

“…The diazine rings are important building blocks of both natural and synthetic compounds, e.g., mononucleotides. This is why, the simplest diazines: pyrazine, pyrimidine and pyridazine, have early attracted attention of chemists [9]. Pyridazine is a heteroaromatic organic compound.…”

Physicochemical and Spectroscopic Characterization of Biofield Energy Treated Gerbera Multiplication Medium

“…Similarly, the peak at 1633 cm -1 in the control sample was assigned to NH 2 deformation that was not observed in the treated sample. Besides, in the control sample the peak appeared as a doublet at 1587 cm -1 was may be due to the ring stretching of the pyridine ring of nicotinic acid and pyridoxine HCl [26]. The peak may also be assigned to the peak due to S-O bond of CuSO 4 and P-O bond of KPO 4 [25].…”

“…Besides, in the treated sample the corresponding peak was observed as a singlet at 1604 cm -1 . The peak at 1344 cm -1 in the control and 1348 cm -1 in the treated sample was assigned to the N-H bend and C-N stretching of pyrimidine ring of thiamine HCl and adenine sulphate [26,27]. Similarly, the peak at 1236 cm -1 in the control and treated sample was assigned to thiazole ring breathing of the thiamine HCl [28].…”

In situ direct photoproduction of ketenes from substituted coumarins isolated in solid argon: The case of N-(2-oxo-2H-chromen-3-yl)acetamide

“…2 A and B). Multiple matrix trapping sites are commonly observed for heterocyclic compounds [32,33] and they were found to be particularly numerous for molecules containing the a-pyrone moiety, including coumarin itself [21]. Explanation for this fact is certainly out of the scope of this study, but appears as an interesting question that might eventually be successfully addressed by using appropriate theoretical approaches (e.g., molecular dynamics).…”