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1.
It is shown that at certain assumptions the tensor of Raman bands can be represented as a sum of the Placzek term and the
fast convergent series that contains information on the sensitivity of the tensor elements to the frequency of exciting radiation.
The convergences of the corresponding series and the frequency dependences of the Raman band intensities for particular molecules
are studied by computer experiments.
Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences. Moscow State Civil-Engineering
University. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 2, pp. 241–249, March–April, 1996.
Translated by I. Izvekova 相似文献
2.
A. I. Khlebnikov 《Journal of Structural Chemistry》1995,36(6):991-994
An algorithm for seeking common structural fragments in compounds of different classes is developed. The algorithm allows
for the molecular geometry and atomic characteristics, It may be used for recognition of compounds with properties associated
with the local similarity of molecules such as ligand complementarity to a receptor. An example of seeking common structural
elements for nondrug analgesics (para-acetamidophenol, acetylsalicylic acid, and amidopyrine) is given.
I. I. Polzunov Altai State Technical University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 1083–1087, November–December, 1995.
Translated by L. Smolina 相似文献
3.
L. V. Akamova V. V. Pinyaskin O. B. Tomilin I. V. Stankevich A. L. Chistyakov 《Journal of Structural Chemistry》1995,36(4):565-571
The problem of stabilizing the linear clusters of mercury by terminal groups is discussed in terms of the MNDO method for
the following model and real compounds: Hgn (I), HgnCl2 (II) and Hgn(AlCl4)2 (III) with n=2–4. It is shown that the terminal acceptor groups stabilize the linear mercury chains. It is established that
in systems (II) and (III), unlike in (I), the highest occupied molecular orbitals are bonding.
Mordoviya State University. Institute of Organoelement Compounds, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 4, pp. 623–629, July–August, 1995.
Translated by I. Izvekova 相似文献
4.
I. V. Makeeva V. G. Kokacheva S. K. Talitskikh P. G. Khalatur 《Journal of Structural Chemistry》1995,36(5):725-733
Solution of the Ornstein-Zernike equation is analyzed numerically in the Percus-Yevick and hyperchain approximations for a
system of Lennard-Jones particles in a critical region. The temperature dependences of correlation functions, isothermal compressibility
η, and correlation radius of density fluctuations ζ are investigated at a critical density; the corresponding critical indices
are determined. It is shown that the Percus-Yevick approximation yields satisfactory results when the correlation functions
are calculated within a range corresponding to approximately 50 atomic (molecular) diameters. In this case, with ≈5% deviations
from the critical temperature, the calculated and experimental values of η and critical indices are in good agreement.
Tver State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 799–807, September–October, 1995.
Translated by I. Izvekova 相似文献
5.
A new model based on certain physical concepts of interatomic interactions is proposed for simulating the volume characteristics
of molecules that allow reliable estimations of the densities of substances and solutions. The model is used to calculate
the solution densities for six substances within wide concentration ranges.
Chelyabinsk State University. Translated fromZhurmal Strukturnoi Khimii, Vol. 36, No. 5, pp. 823–827, September–October, 1995.
Translated by I. Izvekova 相似文献
6.
S. K. Ignatov A. G. Razuvaev V. N. Kokorev Yu. A. Aleksandrov 《Journal of Structural Chemistry》1995,36(4):538-543
Bipolar expansion of the Ohno potential as a method of calculating two-center Coulomb integrals that appear in the NDDO approximation
is generalized to one-center two-electron integrals. A unified semiempirical scheme is suggested for estimating two-electron
interactions in molecules. This scheme can be readily extended to arbitrary Slater basis sets (including the s,p,d-orbitals)
and involves no a priori data on the valent states of atoms. In this work, the scheme is employed to extend the semiempirical
PM3 method to the s,p,d-basis set. The efficiency of the method is proven by test calculations of 24 chromium compounds (π-complexes,
carbonyls, isocyanides, etc.).
Scientific Research Institute of Chemistry at N. I. Lobachevskii Nizhnii Novgorod State University. Translated fromZhurnal Struktumoi Khimii, Vol. 36, No. 4, pp. 593–599, July–August, 1995.
Translated by I. Izvekova. 相似文献
7.
O. V. Sizova A. I. Panin V. I. Baranovskii N. V. Ivanova 《Journal of Structural Chemistry》1996,37(2):171-180
Semiempirical INDO-E/S calculations of [RuX6]q (X=NH3, q=+2, +3; X=CN−, q=−4, −3) complexes are performed to demonstrate that the MO relaxation in the electronically excited state can be taken
into account by introducing certain double excitations into the configuration interaction matrix; the principles of selection
of the excitations are discussed. The calculation results are compared with the experimental electronic absorption spectra.
St. Petersburg State University. Translated fromZhurnal Struktumoi Khimii, Vol. 37, No. 2, pp. 195–205, March–April, 1996.
Translated by I. Izvekova 相似文献
8.
The vibrational structure of the electron transition to the second singlet excited state of pyridine N-oxide has been studied.
The frequency of the 0–0 transition is 34502 cm−1. A computer-aided technique for the assignment of the frequencies of the normal vibrations of polyatomic molecules in the
excited electronic states is proposed. The frequencies of the totally symmetric vibrations of pyridine N-oxide in the second
singlet electronically excited state are assigned.
N. G. Chernyshevskii Saratov State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 350–355, March–April, 1995.
Translated by I. Izvekova 相似文献
9.
V. E. Kuzmin 《Journal of Structural Chemistry》1995,36(5):793-797
This paper examines the possibility of classifying chiral simplices into homochiral subclasses. It is shown that chiral simplices
can skip achiral intermediates to be transformed into another type of homochiral moleucles (stereochemical tunneling).
A. V. Bogatskii Physiochemical Institute, Ukrainian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 873–878, September–October, 1995.
Translated by L. Smolina 相似文献
10.
V. Kh. Kravtsov V. I. Lozan Yu. A. Simonov O. A. Bologa N. V. Gerbeleu T. I. Malinovskii 《Journal of Structural Chemistry》1994,35(3):358-363
Bis-condensation of 4-methyl-2,6-diformylphenol with dimethyl N′,N′-hydrazine diacetate gave product I. The structure of I
was determined by X-ray analysis. The conformations of the two side chains of dimethyl N′,N′-hydrazine diacetate are significantly
different. The position of one chain is fixed by the intramolecular H-bond of O−H.…N type. Due to its conformation, compound
I is partly ready for complex formation with d-metals.
Institute of Applied Physics, Academy of Sciences, Moldova Republic. Institute of Chemistry, Academy of Sciences, Moldova
Republic. Translated fromZhurnal Struktumoi Khimii, Vol. 35, No. 3, pp. 91–98, May–June, 1994.
Translated by L. Smolina 相似文献
11.
Using the crystal-field theory (CFT), we derive equations for the low-spin d5 configuration in the case of an arbitrary ligand field including the configuration interaction correction. Experimental ESR
and electronic absorption spectral data of some octahedral Ru(III) and Os(III) complexes with a strong tetragonal distortion
are analyzed. It is shown that the contribution of the spin-orbit term of the configuration interaction may be considerably
suppressed due to the strong covalency of the σ-bond.
V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 1, pp. 31–48, January–February, 1994.
Translated by L. Smolina 相似文献
12.
É. N. Yurchenko 《Journal of Structural Chemistry》1996,37(2):217-223
The paper describes methods for determining the force fields of large sets of molecules which share the common property that
in their constituent groups of molecules the equivalent force constants always change monotonically with the properties of
substituent atoms belonging to the same subgroup of the periodic table. The force fields of the CH4−nXn (n=0–4, X=F, Cl, Br, I) molecules of the methane series are obtained. The applications of these force fields are discussed.
In particular, they can serve as a basis for a data bank of the force fields of fragments suitable for constructing the force
fields of more complex molecules.
Russian Scientific Center “Applied Chemistry”, St. Petersburg. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 2, pp. 250–256, March–April, 1996.
Translated by I. Izvekova 相似文献
13.
V. P. Koropchanu F. G. Paladii S. I. Boldyrev V. Ya. Gamurar' 《Journal of Structural Chemistry》1996,37(5):707-712
The tunnel states of square-planar bielectron transfer dn-dn-dn+1-dn+1 (n=0–4) clusters are considered. The nature of the ground spin state is revealed in the limiting case of a strong double
exchange. It is shown that the magnetic properties of these systems radically differ from those of clusters with one migrating
electron (hole) and tetrameric tetrahedral bielectron transfer clusters.
Moldova State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 5, pp. 826–833, September–October, 1996.
Translated by I. Izvekova 相似文献
14.
The ionic field effect on metal-olefin π-binding is considered for 24 Cu(I) compounds based on X-ray diffraction data. Structural
features due to Cu…(C=C)−H…An and N−H…An bridges in cationic and zwitterionic π-complexes, respectively, are discussed. Parity
of metal-olefin and hydrogen bonds in formation of these structures is shown.
I. Franko Lvov State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 5, pp. 109–119, September–October, 1994.
Translated by A. Arbuznikov 相似文献
15.
The Raman scattering (RS) tensor as a function of excitation radiation frequency is studied taking into account, the vibration
quantum. It is shown that the corresponding asymmetric components of the tensor are described by fast converging series. Expressions
are obtained for the antisymmetric and symmetric components of the RS tensor. A convenient formula is proposed for the calculation
of the RS tensor and its components, where the tensor is represented as a sum of the derivative of static polarizability and
the terms containing fast converging series. The formula makes it possible to avoid infinite summation. Computer experiments
simulating the dependence of the intensity of RS bands and their components on the excitation frequency are carried out.
Moscow State University of Building Engineering. V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian
Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 6, pp. 1006–1015, November–December, 1996.
Translated by I. Izvekova 相似文献
16.
I. I. Polzunov Altai State Technical University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 4, pp. 737–739, July–August, 1995. 相似文献
17.
The absorption spectra of decapentaene are analyzed and calculated using the available efficient methods of calculating the
matric elements of the vibronic problem, a new parametric method for determining the potential surfaces of excited molecules,
and a fragmentation approach to the design of molecular models. Good agreement for the fine vibrational structure of the calculated
and experimental spectra (differences between the main band frequencies and intensities less than 20 cm−1 and 10%, respectively) is obtained without correcting the parameters of the method. The mechanisms of excitation-induced
structural changes in linear polyenes and the effect of bond angle changes on the vibrational structure of the spectrum are
revealed. A new interpretation of the absorption spectrum of decapentaene in an argon matrix is proposed [J. Mol. Spectrosc.,114, 54–59 (1985)]. It is shown that the parametric method allows quantitative prediction of fine structure for the vibronic
spectra of complex molecules.
K. A. Timiryazev Moscow Agricultural Academy. Translated fromZhurnal Strukturmoi Khimii, Vol. 37, No. 6, pp. 1031–1039, November–December, 1996.
Translated by I. Izvekova 相似文献
18.
The structures, spectra, and electron density distributions of the alumophenylsiloxane (APS) complex and its fragments have
been calculated using semiempirical (AM1) and ab initio (SCF/3-21G and SCF/6-31G*) quantum chemical approximations. It has been shown that the local properties of the central fragment of alumophenylsiloxane,
which is a slightly distorted tetrahedron AlO4, are described with the (LiO)2AlOBe(OH) cluster.
M. V. Lomonosov Moscow State University. I. M. Gubkin State Academy of Oil and Gas. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 3, pp. 410–417, May–June, 1995.
Translated by I. Izvekova 相似文献
19.
Novel approximate methods for calculating the vibrational structure of the electronic spectra of polyatomic molecules—a method
for the direct calculation of the overlap integrals of vibrational wave functions for the electronic states involved in a
transition and a variational method for the solution of the vibrational problem for the excited states—are discussed. The
methods are based on the consideration of the displacement and entanglement of normal coordinates, the quasiorthogonality
of the Dushinsky transformation, and the classification of the states by total vibrational quantum numbers. Matrix perturbation
theory is employed. It is shown that the accuracy of these methods compares well with the accuracy of the available “exact”
techniques (the errors are ∼1 cm−1 for frequency and 10% for relative intensity). At the same time, calculations by the new methods are performed more than
two orders of magnitude faster than by the previously known methods.
K. A. Timiryazev Agricultural Academy, Moscow. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 217–230, March–April, 1995.
Translated by I. Izvekova 相似文献
20.
L. A. Gribov 《Journal of Structural Chemistry》1995,36(6):1046-1048
V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 1142–1144, November–December, 1995 相似文献