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1.
A comparative vibrational spectra study of 2- and 4-CH3, −NO2 and Br-derivatives of some 3,5-dialkylbenzoic acids (R:-Me, −Et, −Pri, −But) is carried out. We propose an explanation of its molecular structure. 相似文献
2.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1990,46(12):1779-1791
The vibrational spectra of N-methylpyridinium iodide and three of its selectively deuterated derivatives have been recorded in the crystalline as w 相似文献
3.
Infrared and Raman spectra of diacetylene-d0, -d1, and -d2 have been recorded and a complete vibrational analysis is proposed for each of these three species. 相似文献
4.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1976,32(5):1089-1104
The i.r. and Raman spectra of tellurophene, tellurophene-2-d1, tellurophene-2-5-d2, tellurophene-3-4-d2, tellurophene-2-3-4-d3 and tellurophene-2-3-4-5-d4 have been studied. A vibrational assignment of the fundamental frequencies of all these molecules has been carried out on the basis of i.r. vapor band contours and depolarization states of Raman lines. Such an assignment conveniently fits the isotopic “sum” and “product” rules. A comparison of the vibrational behaviour of tellurophene and that of the other congeners is made and a rationalization of some frequency shifts is attempted. 相似文献
5.
The infrared and Raman spectra of the H2PO2?, HDPO2? and D2PO2? ions have been measured in aqueous solutions. The assignment of bands to the fundamental vibrations proposed is based on experimental tests, band polarisation measurements, application of all known isotopic rules and the construction and analysis of all the physically admissible assignments. The thermodynamic functions of the studied ions are calculated in the rigid rotator and harmonic vibrator approximation. 相似文献
6.
F. J. Boerio S. K. Bahl G. E. McGraw 《Journal of Polymer Science.Polymer Physics》1976,14(6):1029-1046
The Vibrational analysis of polyethylene terephthalate, polyethylene-d4 terephthalate, and polyethylene terephthalate-d4 has been carried out using a valence force field calculated from the infrared and Raman spectra of a series of low molecular weight aromatic esters. The Raman spectra for polyethylene-d4 terephthalate and polyethylene terephthalate-d4 are presented and band assignments for these compounds and polyethylene terephthalate are discussed. 相似文献
7.
Shlyapochnikov V. A. Levchenkov D. V. Kharitonkin A. B. 《Russian Chemical Bulletin》2001,50(7):1173-1180
Spectroscopic parameters of trinitromethane derivatives RC(NO2)3 (R = F, Cl, Br, I, NC, NF2, N3) were determined. Vibrational frequencies and modes were calculated and the assignment of experimental spectra was performed. Spectral features due to the mutual influence of the C(NO2)3 group and other atomic groups and particular atoms were revealed. 相似文献
8.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1988,44(11):1165-1184
The i.r. spectra of gaseous, amorphous and crystalline solid and the Raman spectra of liquid and amorphous solid chloromethylacetate, CH3COOCH2Cl, and three deuterated derivatives, CH3COOCD2Cl, CD3COOCH2Cl and CD3COOCD2Cl, were obtained and an assignment proposed. Only one conformer of CMA was found to be present in all phases. Band contour simulation of the i.r. vapour phase bands showed this to be the s-cis gauche conformer. This was confirmed by a study of the partially deuterated compound CD3COOCDHCl, of which the separate transitions originating from the antiperiplanar and synclinal isolated CH stretches were observed in the i.r. spectra of the vapour and crystalline solid and in the Raman spectrum of the vapour. 相似文献
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10.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1988,44(7):749-761
I.r. and Raman spectra of p-cresol and its seven deuterated analogs were investigated in dilute solutions of hydrophobic solvents. Assignments of the observed i.r. and Raman bands were made on the basis of isotopic frequency shifts, Raman polarization properties, i.r. intensifies and normal coordinate calculations. The calculated normal frequencies are in good agreement with the experimental ones: the average error below 1700 cm−1 is 3.8 cm−1 for 164 in-plane vibrations and 3.3 cm−1 for 59 out-of-plane vibrations. The calculated vibrational modes may be useful in analysing the vibrational spectra of tyrosine. It is suggested that several doublets due to Fermi resonance and a trio of Raman bands in the 1260-1160 cm−1 region are potential probes for the micro-environments of tyrosine side chains in proteins. 相似文献
11.
V. B. Mel'nikov L. F. Baeva V. V. Stolpakova M. S. Pevzner B. V. Gidaspov 《Chemistry of Heterocyclic Compounds》1977,13(6):686-689
The frequencies and forms of the normal vibrations of a number of azido derivatives of 1,2,4-triazole [3-bromo-5-azido-(I), 1-methyl-3razido-(II), and 3-azido-5-nitro-1,2,4-triazole (III)] were calculated. The inverse spectral problem for the parameters of the azido group was solved by the method of least squares. A similar method was used to calculate the potential energy constants of the triazole ring with the aid of data on the force fields of the previously investigated nitrotriazoles. It is shown that the introduction of electron-donor or electron-acceptor substituents in the triazole ring does not affect the force constants of the CN and NN bonds of the azido group. Transmission of the electronic effects in the ring as a function of the nature and position of the substituent was investigated.See [1] for communication V.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 839–842, June, 1977. 相似文献
12.
V. V. Mel'nikov V. V. Stolpakova S. A. Zacheslavskii M. S. Pevzner B. V. Gidaspov 《Chemistry of Heterocyclic Compounds》1973,9(10):1289-1295
The frequencies and forms of the normal vibrations of the anions of 1,2,4-triazole and 3-nitro-, 3-nitro-5-methyl-, and 3,5-dinitro-1,2,4-triazoles were calculated. The potential energy constants were calculated by solution of the reciprocal spectral problem, and the frequencies in the experimental spectra were assigned to the fundamental types of normal vibrations. It is shown that the nitro groups in the 3 and 5 positions in the anions of the triazoles are located in the plane of the triazole ring. The coordination of the metal in crystalline salts of nitrotriazoles was studied by the methods of vibrational spectroscopy, and an assumption is stated that the most probable position of the metal is near the oxygen atoms of the nitro group along the Me-O-N line. As a result of a theoretical analysis of the vibrational spectra of the anions it was ascertained that equalization of the lengths of the ring CN bonds does not occur during ionization of the covalent triazoles. Calculations by the MO LCAO SCF method are in agreement with the data from vibrational spectroscopy.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1423–1431, October, 1973. 相似文献
13.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1987,43(10):1209-1230
The ground state vibrational spectra of E-hexatriene, Z-hexatriene, E,E-heptatriene, E,E,E-octatriene, and E-2,5-dimethyl-hexatriene are reported. For E- and Z-hexatriene complete vibrational assignments, and for heptatriene, octatriene, and dimethyl-hexatriene near-complete assignments are obtained. The effects of terminal and lateral methyl-substitution are compared. 相似文献
14.
V. V. Mel'nikov V. V. Stolpakova M. S. Pevzner B. V. Gidaspov 《Chemistry of Heterocyclic Compounds》1973,9(9):1085-1088
From an analysis of the IR and Raman spectra and a calculation of the frequencies and forms of the normal vibrations of the nitrotriazoles, conclusions have been drawn on the structure of 3,5-dinitro-1,2,4-triazole and 1-methyl-3,5-dinitro-1,2,4-triazole. The nitro group in position 3 of the triazole ring is located in the plane of the molecule, and that in position 5 is rotated about the CN bond. The spatial nonequivalence of the nitro groups leads to the splitting of the absorption bands in the IR spectra that are characteristic for the anti- and synphase vibrations of the nitro groups.For Communication (II), see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1194–1198, September, 1973. 相似文献
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V. V. Mel'nikov V. V. Stolpakova M. S. Pevzner B. V. Gidaspov 《Chemistry of Heterocyclic Compounds》1973,9(5):651-655
The frequencies and forms of the normal vibrations of 3-nitro-1,2,4-triazole, its 1-deuteroand 1-methyl derivatives, and 1-methyl-3-nitro-5-chloro(bromo)-1,2,4-triazole, which are classified as having CS group symmetry, were calculated. The potential energy constants were refined by solution of the reciprocal spectral problem, and the frequencies in the experimental spectra were assigned to the principal types of vibrations.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 707–712, May, 1973. 相似文献
18.
V. V. Mel'nikov V. V. Stolpakova B. V. Gidaspov 《Chemistry of Heterocyclic Compounds》1972,8(11):1417-1420
The vibrational spectra of 1,2,4-triazole and its 3-chloro and 3-bromo derivatives were calculated for the CS point symmetry group. The potential energy constants were computed, and it is shown that the force field of the triazole ring has the additivity property; i.e., it remains practically constant when electron-acceptor groups such as chlorine and bromine are introduced into the 3 position. The force constants of interaction of the valence and angular coordinates of the ring have high values; this is a characteristic of the considerable rigidity of the triazole ring. The fundamental frequencies in the experimental spectra were assigned on the basis of an analysis of the calculated forms of the normal vibrations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1567–1570, November, 1972. 相似文献
19.
V. V. Mel'nikov L. F. Baeva V. V. Stolpakova M. S. Pevzner M. N. Martynova B. V. Gidaspov 《Chemistry of Heterocyclic Compounds》1974,10(9):1117-1120
The frequencies and forms of the normal vibrations of 3-azido- and 3-azido-5-methyl-1,2,4-triazoles and their 1-deutero-substituted derivatives were calculated, the effect of the geometrical parameters of 3-azido-1,2,4-triazole on the vibrational spectra was investigated, and the most probable three-dimensional model of the molecule was selected. The solution of the inverse spectral problem was effected by the method of least squares, and the potential energy constants of the azidotriazoles were calculated. It is shown that the force constants of the azido group increase and the elastic constants of the ring decrease when an azido group is introduced into the 1,2,4-triazole molecule. The frequencies in the experimental spectra were assigned to the principal types of normal vibrations. 相似文献
20.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1989,45(2):305-313
Raman and i.r. spectra of tetramethylcyclobutane-1-one-3-thione (TMCBOT) and the fully deuterated derivative TMCBOT-d12 have been recorded. A fairly complete set of vibrational frequencies and assignments are given for the two molecules. The CO stretching mode was observed as a very strong Fermi doublet in the infrared spectrum of TMCBOT at 1811/1782 cm−1. For TMCBOT-d12 a similar doublet was observed at 1808/1775 cm−1. The CS stretching mode was assigned to bands at 1303 cm−1 for TMCBOT and 1307 cm−1 for the deuterated molecule. 相似文献