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1.
Based on calculation of frequencies and modes of normal vibrations of salts of N-acyl-4-dimethylaminopyridinium with N-acyl
groups of different structures (acetyl, methoxycarbonyl, dimethylcarbamoyl), an interpretation is given of the IR spectra
of the corresponding N-acyloinic cations. It is shown that the differences recorded in the experimental spectra of the salts
are due to interaction between skeletal deformational vibrations of the aromatic ring and the deformational vibrations of
acyl groups and to the manifestation of the characteristic vibrations of proper acyl groups. The stretching and deformational
vibrations of the 4-dimethylamino group are insensitive to the nature of the acyl fragment.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 26–28, January–February, 2000. 相似文献
2.
Symmetry properties of generalized mean-square vibration amplitudes for plane six-membered rings belonging to the C2v and D6h symmetry groups are investigated. Corrections to average and equilibrium interatomic distances in benzene, pyridine, and
N-oxypyridine are calculated. The character of the corrections in the series of these molecules and their deuterosubstituted
analogs is investigated.
Saratov State University, 83, Astrakhanskaya St., Saratov, 410601, Russia. Translated from Zhurnal Prikladnoi Spektroslopii,
Vol. 65, No. 2, pp. 192–195, March–April, 1998. 相似文献
3.
O. M. Zharkova Yu. P. Morozova A. A. Lukashevskaya V. Ya. Artyukhov B. V. Korolev 《Russian Physics Journal》2008,51(1):10-17
Using the method of intermediate neglect of differential overlap (INDO), quantum-chemical investigations of geometrical prodan
structures with different rotation and deflection angles of methyl groups in the dimethylaminogroup of the molecule are performed.
The charge distribution is studied for different conformations of the molecule. The possible centers of prodan interaction
with proton-donor solvents are estimated. It is demonstrated that in addition to the oxygen and nitrogen atoms, the carbon
atoms of the hydrocarbon chain and the aromatic prodan ring can interact with the solvent.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 10–16, January, 2008. 相似文献
4.
Saratov State University, 83 Astrakhanskaya Str., Saratov, 410601, Russia. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 62, No. 6, pp. 49–57, November–December, 1995. 相似文献
5.
A. I. Skotnikov 《Journal of Applied Spectroscopy》1997,64(2):265-271
The most important aspects in solving inverse and direct spectroscopic problems in the second order of perturbation theory
in the presence of Coriolis, Fermi, and Darling-Dennison resonances are discussed. A scheme for obtaining unperturbed values
of spectroscopic parameters is suggested which has some advantages over that proposed earlier in [6]. It is believed that
this information can be useful to specialists in the field of applied spectroscopy.
Saratov State Technical University, 77, Politechnicheskaya St., Saratov, 410054, Russia. Translated from Zhurnal Prikladnoi
Spektroskopii, Vol. 64, No. 2, pp. 249–255, March–April, 1997. 相似文献
6.
Scientific-Research Institute of Mechanics and Physics at the Saratov State University, 112-A, Bolshaya Kozach'ya Str., Saratov,
410071, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 3, pp. 235–238, May–June, 1995. 相似文献
7.
N. A. Borisevich D. K. Buslov V. N. Zhabinskii V. A. Khripach 《Journal of Applied Spectroscopy》2009,76(5):617-622
IR spectra of steroid phytohormones of the stigmastane series (22R, 23R)-28-homocastasterone and (22R,23R)-28-homosecasterol
and their isomers (22S,23S)-28-homocastasterone and (22S,23S)-28-homosecasterol have been analyzed. The 28-homocastasterone
molecule contains diol groups in ring A and in the side chain whereas that of 28-homosecasterol has one diol group in the
side chain. The lack of two OH groups in ring A of homosecasterol compared to homocastasterone results in the appearance of
stretching vibrational bands of H–C= (νmax = 3025 cm–1) and –C=C (νmax = 1656 cm–1) groups of ring A. Substantial changes are observed in the area of OH stretching vibrations. Homocastasterones pressed in
KBr possess twice as many OH groups as homosecasterols such that absorption band total intensities in IR spectra of both isomers
caused by H-bonds of the diol groups in the side chain amount to 65% whereas the share of the 2α,3α group is only 35% of the
total intensity. Hence the contribution from the side-chain OH groups of the studied brassinosteroids to the integral optical
density of the bands exceeds that from the ring-A OH groups. In dilute CHCl3 solutions of the brassinosteroids, the conformations
of the brassinosteroid side chains are not the same. As a result, intramolecular H-bonds of different energy are created.
The optical density Dmax in band maxima of free OH groups for homocastasterones is three times higher than that for the corresponding band maxima
of homosecasterol. This implies that Dmax for bands of free OH groups of the homocastasterone ring-A diol group is greater, in contrast with the relatively greater
Dmax for bands of homosecasterol side-chain OH groups bound by an intermolecular H-bond. The homocastasterone diol groups also
form intramolecular Hbonds more actively. The lack of the diol group in ring A of the homosecasterols does not affect the
frequencies of the C=O stretching vibrations. This leads to the conclusion that the C=O group forms intermolecular H-bonds
only with the side-chain OH groups of brassinosteroids pressed in KBr. 相似文献
8.
Infrared spectra of brassinolide and castasterone steroid phytohormones and their 24-epi derivatives
Absorption bands in IR spectra of brassinolide, castasterone, and their 24-epi derivatives in the frequency range 3800–1000
cm–1 have been interpreted. A number of spectral features distinguishing brassinolide from castasterone have been found. The conducted
analysis shows that the structural differences manifest themselves in IR spectra of the investigated brassinosteroids in the
region of stretching vibrations of CO–H, C=O, C–OH, C–O–C, CH3, CH2, and CH groups. The main distinctions in IR spectra of brassinolides and castasterones are due to the B ring structure. 相似文献
9.
Lengyel L Gyóllai V Nagy T Dormán G Terleczky P Háda V Nógrádi K Sebok F Urge L Darvas F 《Molecular diversity》2011,15(3):631-638
Aromatic or heteroaromatic ring precursors with 2–3 identical functionalities are often used in sequential derivatization
depending on the reactivity difference or the selective execution of the reaction such as nucleophilic aromatic substitution.
Continuous flow chemistry offers an enhanced parameter space (pressure and temperature) with rapid parameter optimization
that ensures selectivity in many cases. We developed a flow chemistry procedure to carry out a stepwise aromatic nucleophilic
substitution of difluoro-benzenes having an activating group in meta position to the fluorines. The mono-aminated products were obtained in high yield and selectivity in an extremely short reaction
time, while applying higher temperature, longer reaction zone (or time), and employing higher excess of another amine reactant,
the subsequent introduction of the second amino group was also successfully achieved leading to an unsymmetrically substituted
3,5-diamino-benzonitrile library. 相似文献
10.
A calculation of the frequencies and forms of the normal vibrations of the 31-atom molecule 2,3-di-O-nitromethyl-β-D-glucopyranoside
has been performed. Particular emphasis has been placed on the interpretation of the strongest bands in the spectrum of 2,3-di-O-nitro-methyl-β-D-glucopyranoside,
which are due to vibrations of the nitrate groups.
The present work has been reported at the IV International Congress of theoretically competent chemists, Jerusalem (Israel),
July 7–12, 1996.
B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 724–728, November–December, 1997. 相似文献
11.
N. I. Garbuz Yu. A. Sokolov L. P. Solovei R. P. Litvinovskaya S. V. Drach A. V. Baranovskii V. A. Khripach 《Journal of Applied Spectroscopy》2006,73(2):155-163
We have used IR spectroscopy and the quantum chemical AM1 method to study stereoisomeric 22(23)-isoxazolinyl steroids with
a hydroxyl group at C20 or C22, in order to establish the spectral features that will allow us to identify their stereoisomers. We have carried out a conformational
analysis of isoxazolinyl steroid stereoisomers, and we have calculated the populations of their stable conformers. We have
assigned the bands in the IR spectra of the stereoisomers in the region of the stretching vibrations of OH groups, and have
analyzed the possibility of intramolecular hydrogen bond formation between the OH groups and proton-acceptor centers of the
isoxazoline ring.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 145–151, March–April, 2006. 相似文献
12.
It is shown that, upon formation of ultrasound jet-cooled var der Waals complexes of polar molecules of 9-cyanoanthracene,
3-aminophthalimide, and 3-amino-N-methylphthalimide with water molecules, pronounced manifestations of isotope substitution
in the ligand molecules take place, which manifest themselves in shifting 0–0-transitions by 5–7 cm−1 and changes in frequencies of intramolecular vibrations. Spectroscopic effects of isotope substitution of atoms of the amino
group are established for substituted phthalimides. We propose a new mechanism of the effect of isotope substitution on frequencies
of electronic transitions which cannot be reduced to the known one (realized by means of changes in values of the zero vibrational
energy) and is based instead on the change in the charge density distribution in the molecule.
Belarusian State University, 4, F. Skorina Ave., Minsk 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 2, pp. 148–154, March–April, 1997. 相似文献
13.
N. A. Borisevich V. A. Povedailo E. E. Tselesh D. L. Yakovlev 《Journal of Applied Spectroscopy》2007,74(6):838-843
We have analyzed the fluorescence excitation spectra of carbazole complexes with a single molecule of methyl, deuterated methyl,
ethyl, and propyl (1-propanol and 2-propanol) alcohols, cooled in a supersonic jet. We have determined the shifts in the fluorescence
excitation spectra of the complexes relative to the frequency of the purely electronic transition of unbound carbazole. They
occur as a result of formation of hydrogen bonds between the N-H group of the carbazole and the OH group of the alcohols.
The frequencies of stretching vibrations of the hydrogen bonds with different alcohols vary within the range 150–157 cm−1, while the frequencies of the bending vibrations vary in the range 21–22.9 cm−1. From the shape of the rotational contours of the bands for the purely electronic and vibronic transitions of the complexes,
we determined that they belonged to rotational conformers. We calculated the equilibrium configurations of the complexes in
the ground state.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 756–760, November–December, 2007. 相似文献
14.
In a harmonic approximation we calculate the frequencies of normal vibrations and their modes for a salt cation of N-acethyl-4-dimethylaminopyridinium
hexachlorstibiate and of its three deuteroderivatives obtained on deuteration over a CH3-group, over a ring, and over a ring and a CH3-group. From the results of calculation, an interpretation of the IR spectra of the salts considered is carried out.
To whom correspondences should be addressed.
L. M. Litvinenko Institute of Physical and Organic Chemistry and the Chemistry of Coal, National Academy of Sciences of Ukraine,
70, R. Luxemburg Str., Donetsk, 340114, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 158–162,
March–April, 1999. 相似文献
15.
For the first time, we have assigned the observed absorption bands and interpreted the IR spectrum of methyl-β-D-glucopyranoside
in detail in the 1500–800 cm−1 region, based on a full calculation of the frequencies and absolute intensities of the normal vibrations of the molecule
and their comparison with the experimental data. We have identified two groups of spectral signs indicating an oxymethyl substituent
has replaced the hydroxyl group on the C(1) atom in the glucopyranoside: absorption bands of medium intensity due to the characteristic vibrations of the substituent,
and intense bands due to an unusual “interaction” between many structural moieties.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 721–727, November–December, 2006. 相似文献
16.
N. A. Borisevich D. K. Buslov V. A. Khripach V. N. Zhabinsky 《Journal of Applied Spectroscopy》2008,75(5):637-643
Comparative analysis of IR spectra of S-and R-isomers differing in the configuration of OH groups in the side chain of biologically
active 24-epi-and 28-homocastasterones and 24-epi-and 28-homobrassinolides is carried out. Stretching vibration frequencies
of H-bonded OH groups of isomers of corresponding brassinosteroids practically coincide. The optical density in maxima of
these bands is higher in spectra of the R-isomers. Alteration in the configuration of the OH groups weakly influences also
the band intensities of CH3, CH2, and CH groups. Band intensities of stretching vibrations of associated C=O groups of S-and R-isomers also neglibibly differ
from each other. Their frequency characteristics do not experience substantial changes. These features differ considerably
in IR spectra of castasterones and brassinolides. For castasterones, the difference in frequencies of band maxima of free
and bound C=O groups amounts to ∼15 cm−1; for brassinolides, 23 cm−1. Intensities of both bands are approximately equal in spectra of castasterones. The band intensity of free C=O groups of
brassinolides is considerably lower than that of H-bonded ones. The above spectral differences can be used to identify these
brassinosteroids. Frequencies of both symmetric and antisymmetric deformation vibrations of CH3 and CH2 groups are close in spectra of all brassinosteroids studied. The frequency of CH2 in a CH2-OC group belongs only to brassinolides; of deformation vibrations of CH in a CH-C=O group, to castasterones. The frequency
of stretching vibrations of C-O-C and C-O groups is observed only in spectra of brassinolides. In the region 1130–900 cm−1 of IR spectra of brassinosteroids, stretching vibrations of CC, CCH, and C-OH groups are predominantly observed. In the frequency
range 1130–995 cm−1, the optical density of band maxima of S-isomers is higher than that of R-isomers, which can be used to identify isomers.
At the same time frequencies of corresponding bands of isomers practically coincide. Differences in the structure of the side
chain of brassinosteroids do not influence essentially the frequency characteristics of the IR spectra. The exception is the
band related to stretching vibrations ν(C23-OH) of the side chain which features a considerable frequency νmax ≈ 983 cm−1 only in spectra of R-isomers of homocastasterone and brassinolide.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 623–630, September–October, 2008. 相似文献
17.
We present the results of a spectral study of the effect of low-intensity laser radiation on the molecular structure of blood
and blood components. Analysis of the Fourier transform IR absorption spectra of blood confirmed the changes we observed previously
in the oxygen transport characteristics of blood with intravenous exposure to the emission from a He-Ne laser. We show that
structural and conformational changes in the hemoglobin tetramer, initiated by laser-induced photoreactions between Hb and
oxygen, lead to characteristic changes in the shape and intensity of the IR bands for NH stretching vibrations, and also the
amide I and amide II absorption bands. In the IR spectra of irradiated blood samples, we note increased absorption in the
bands for stretching vibrations of the phosphate groups (945–1280 cm−1), which is evidence for an increase in the nucleic acid content (DNA, RNA). In the spectra of plasma and erythrocytes prepared
from irradiated blood, there are no changes in this region of the IR spectrum. At the same time, in the IR spectra of samples
of irradiated plasma, the intensity of the bands for stretching vibrations of the CH2 groups increases substantially.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 106–112, January–February, 2006. 相似文献
18.
We show that in describing the vibrations of molecules it is worthwhile to use coordinates that include the mass centers of
atomic groups. We note special features of the program implementation of the approach in application to the earlier devised
set of “Spectrum-structure” and LEV programs.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 42–47, January–February, 2000. 相似文献
19.
A. N. Kislov V. G. Mazurenko V. I. Sokolov A. N. Varaksin 《Physics of the Solid State》1999,41(6):897-901
Localized vibrations in ZnO crystals due to the substitution impurity Ni+1 are modeled. The calculations were performed in the shell model using a recursive method for vibrations with A
1 and E type symmetry. Numerical calculations allowed us to analyze the vibronic structure in the electro-absorption spectra for
nickel acceptor excitons in ZnO:Ni.
Fiz. Tverd. Tela (St. Petersburg) 41, 986–990 (June 1999) 相似文献
20.
We show that oscillations in the generating circuit are stimulated under the action of microwave radiation when bias voltage,
which is smaller than peak voltage, is applied to the diode. In this case, the frequency and amplitude of the generation stimulated
by microwave radiation depend on the radiation power level.
Saratov State University, Saratov, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No.
10, pp. 1009–1012, October 1999. 相似文献