共查询到20条相似文献,搜索用时 46 毫秒
1.
I. M. Krukovskii M. S. Molchanova A. V. Evtushenko V. A. Shlyapochnikov 《Russian Chemical Bulletin》1998,47(7):1266-1273
The ratio between the numbers of structural formulas of C,H,N,O-containing energetic compounds belonging to the classes of
fuels (low values of the oxygen coefficientA), explosives (mediumA), and oxidants (highA values) was studied by a computer generation procedure. The number of the theoretically possible structural formulas was
found to decrease rapidly on going from fuels to explosives and then to oxidants; this observation agrees with the data on
the numbers of various energetic compounds currently used and proposed. The strategy of the search for new compounds with
the specified properties is described in brief, and its applicability to the search for explosives and oxidants with a small
(up to 12) number of atoms in a molecule is evaluated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1304–1310, July, 1998. 相似文献
2.
3.
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
4.
The geometrical structure, force fields, and parameters of vibrational-rotational interaction of six-membered azacyclic compounds
in the ground and excited states are estimated using the structural dynamic model of a polyatomic molecule.
Translated fromZhurnal Struktumoi Khimii, Vol. 38, No. 2, pp. 345–349, March–April, 1997. 相似文献
5.
V. N. Piottukh-Peletskii B. G. Derendyaev O. N. Sharapova 《Journal of Structural Chemistry》2000,41(2):309-317
Representation of a structural formula of a compound as a complete set of nonisomorphic k-vertex (2 ≤k≤7) connected fragments
is used to evaluate the structural similarity of compounds. The spectra and structures of spectrally or structurally alike
compounds are compared statistically using a database containing 32,000 IR spectra and structures. This study reveals some
tendencies typical for both full IR spectra and their abbreviated versions represented by sets of most characteristic peaks.
Applicability of IR databases to spectrum simulation for compounds with a specified structure is justified statistically.
A method is proposed for evaluating the efficiency of a search algorithm selecting structural analogs of the compound from
an IR database according to the query spectrum.
Translated fromZhurnal Strukturnoi Khimii, Vol. 41, No. 2, pp. 379–390, March–April, 2000. 相似文献
6.
The results of NMR spectroscopy on203,205Tl,207Pb,125Te, and other nuclei are used to characterize an anomalous effect of the s2 lone pair on interatomic interactions in the fluorides, oxides, and chalcogenides of some elements of Groups 13–18 of the
periodic table. Data for crystals of TISe structural type and related compounds, for various structural modifications of TIF,
PbO, and TeO2 crystals, and also for liquids and liquid solutions [(TIOC2H5)4, (XeF6)4, etc.], of vanadium tellurite and lead silicate glasses are considered. It is shown that the electronnuclear interactions
and the structural peculiarities of compounds with underoxidated cations are due to the effect of the excited states of ions
with the electronic configuration s2.
Translated fromZhumal Strukturnoi Khimii, Vol. 38, No. 1, pp. 173–195, January–February, 1997. 相似文献
7.
N. V. Podberezskaya S. A. Magarill N. V. Pervukhina I. G. Vasilieva S. V. Borisov 《Journal of Structural Chemistry》1996,37(6):963-985
The structures of rare earth dichalcogenides are investigated. The symmetry and unit cell parameters are considered, and their
relationship with those of the PbFCl and anti-Cu2Sb structural prototypes is analyzed. The interatomic distances in the Ln3+, X2−, and (X2)2− layers and the compatibility factors are examined. It is discussed how the degree of polymerization of the chalcogen ions
in the (X2)2− layers and the compatibility of the latter with the Ln3+ and X2− layers affect the symmetry and the twinning and polymorhism abilities of the compounds.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 6, pp. 1140–1170, November–December, 1996.
Translated by L. Smolina 相似文献
8.
L. M. Babkov O. V. Gorshkova N. A. Golovina G. A. Puchkovskaya I. N. Khakimov 《Journal of Structural Chemistry》1995,36(2):302-308
Polymorphism and the structure of mesomorphous states of long-chain aliphatic compounds (LAC) have been studied by vibrational
spectroscopy (theory, experiment) using calorimetry, polarizing microscopy (PM), and X-ray diffraction (XRD) analysis as auxiliary
methods. LAC are represented by homologous series of alkyl- and alkoxybenzoic acids, alkylcyclohexanecarboxylic acids, their
completely or partially fluoroalkyl-substituted analogs, and 4-cyano-4′-(n-alkoxy)biphenyls. The studies were performed at
77–500 K. IR absorption and Raman spectra were measured at 30–4000 cm−1. The compounds are characterized by conformational polymorphism. The molecules and their H-complexes undergo structural rearrangements
during phase and conformational transitions. In the course of the rearrangements, alkyl and fluoroalkyl radicals (AR and FAR)
are twisted, and carboxyl groups are disordered. The rearrangements dictate the structure of mesophases, which are mostly
formed of H-complexes consisting of dimers, monomers, and open associates.
N. G. Chernyshevskii Saratov State University. Institute of Physics, Ukrainian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 338–344, March–April, 1995.
Translated by L. Smolina 相似文献
9.
Formononetin and the new isoflavonoid glycosides formononetin-7-O-β-D-galactopyranoside and inermin-3-O-β-D-galactopyranoside were isolated from Trifolium pratense L. roots. The structures of the isolated compounds were proved using chemical transformations and UV, PMR, and 13C NMR spectra.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 21–23, January–February, 2008. 相似文献
10.
S. A. Magarill S. V. Borisov N. V. Podberezskaya E. N. Ipatova V. A. Titov F. A. Kuznetsov 《Journal of Structural Chemistry》1995,36(3):510-513
The Inorganic Crystal Structure Database is a section of the Databank on the Properties of Materials for Electronics that
was created at the Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. The database, which is
supplied with constantly updated software, includes quantitative structural data and is designed for solving materials-technology
problems. The database contains information on crystal structures of complex and ordinary oxides (including compounds with
HTSC properties), chalcogenides, intermetallic compounds, inorganic complexes, etc. More than 20 scientific works on different
topics were performed using the database.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 3, pp. 559–563, May–June, 1995.
Translated by L. Smolina 相似文献
11.
I. G. Zenkevich 《Journal of Structural Chemistry》1996,37(4):674-682
It is shown that using additive schemes complying with the general principle of structural analogy for all molecular transformations
is admissible for calculating gas chromatographic retention indices, which are very important analytical parameters for identification
of organic compounds. From this viewpoint, we compare the possibilities of using the homomorphism factors and the fit increments
of the retention indices of reagents and products in chemical reactions, including those of some topochemically equivalent
hypothetical transformations of the structure and composition of organic molecules.
Scientific-Research Institute of Chemistry, St. Petersburg University. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 4, pp. 784–795, July–August, 1996.
Translated by L. Smolina 相似文献
12.
I. S. Mikhel K. N. Gavrilov A. I. Polosukhin A. I. Rebrov 《Russian Chemical Bulletin》1998,47(8):1585-1588
Reactions of phosphoramidites based on (−)-ephedrine and [(1S)-endo]-(−)-borneol with the complexes M(COD)Cl2 (M is Pd or Pt, and COD is cycloocta-1,5-diene) were studied. The formation ofcis andtrans complexes of the general formulas MCl2L2 and M2Cl2(μ-Cl)2L2 was observed. The structures of the resulting compounds were established by31P,13C, and195Pt NMR and IR spectroscopy and by plasma desorption mass spectrometry.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1627–1630, August, 1998. 相似文献
13.
L. I. Makarov 《Journal of Structural Chemistry》1997,38(4):666-672
The method and algorithms for predicting properties of chemical compounds by their quantitative structural characteristics,
in particular, molecular graph indices, are presented. The prediction procedure consists of establishing the priority of indices
for training sample compounds, classifying control sample compounds in the Euclidean space of indices, and finding a locally
optimum (informative) index set giving a least prediction error. The algorithms have been successfully tested using the BACC
system (analysis and classification of biologically active compounds), created at the S. V. Sobolev Institute of Mathematics
of the Siberian Branch of the Russian Academy of Sciences.
Translated fromZhumal Strukturnoi Khimii, Vol. 38, No. 4, pp. 795–802, July–August, 1997. 相似文献
14.
Formononetin, prunetin, genistein, genistin, and a new genistein glycoside genistein-7-O-β-D-galactopyranoside were isolated from the aerial part of Trifolium pratense L. The structures of the isolated compounds were established based on chemical transformations and UV, 1H, and 13C NMR spectra.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 141–143, March–April, 2008. 相似文献
15.
G. K. Oleinikova O. I. Ivchuk V. A. Denisenko E. L. Chaikina N. I. Menzorova O. I. Nedashkovskaya T. A. Kuznetsova 《Chemistry of Natural Compounds》2006,42(6):713-717
N-Acetyl-(1) and N,N-diacetyl-(2) tryptamines were isolated from the butanol extract of culture medium of the new marine bacterium Roseivirga echinicomitans KMM 6058T. The structures of the compounds were proved using mass spectrometry, UV, PMR, and 13C NMR spectroscopy and by comparing these data with mass and NMR spectra of synthetic samples of 1 and 2. Compound 2 was isolated from a natural source and synthesized for the first time. The cytotoxic activity of the compounds was studied
using Erlich carcinoma tumor cells, murine erythrocytes, and sperm and egg cells of the sea urchin Strongylocentrotus intermedius.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 581–584, November–December, 2006. 相似文献
16.
V. P. Novikov S. A. Tarasenko S. Samdal L. V. Vilkov 《Journal of Structural Chemistry》2000,41(2):217-230
The geometrical parameters for 1,1-dimethylsilacyclobiitane and 1,1,3,3-tetramethyl-13-disilacyclobutune are detemiined by
gas phase electron diffraction analysis using a dynamic model, which considers ring inversion as a large-amplitude motion.
The structural and potential function parameters were refined with allowance for molecular geometry relaxation estimated by
quantum chemical calculations with an HF/6-311G** basis. The potential function of 1,1-dim ethylsilacyclobutane is represented
as V(ϕ) = V0[(ϕ/ϕe)2 − 1]2 with V0 = 1.3 ± 1.2 kcallmole and ϕe = 29.7±4.5°, where ϕ is the ring puckering angle. A more reliable estimate for the height of the barrier (V0 = 0.56 kcallmole) was obtained by solving the one-dimensional quantum vibrational problem and by fitting the frequency of
the 0 →2 transition to the experimental value. For 1,1,3,3-tetram ethyl-1,3-disilacyclobutane, the potential function is adequately
represented bx V(ϕ) = Aϕ2, where A = (4.9 ± 1.8) · 10−4 kcall(mole · deg2) with a minimum coiresponding to a planar ring conformation with ϕ = 0°. The calculated structural parameters are compared
with the data for related compounds.
Translated fromZhumal Struktumoi Khimii. Vol. 41, No. 2, pp. 269–284, March–April, 2000 相似文献
17.
Ab initio quantum chemical calculations of the divinylacetylene molecule with different mutual orientations of vinyl groups
are carried out using the 6–31G*/MP2 basis set. The torsional potential is approximated by a Fourier series. It is shown that
the second term of the series dominates. The enthalpies of the cis- and trans-isomers are nearly equal; the maximum corresponds
to the gosh-orientation (180.4 cm−1 with respect to the cis-form). The vibrational spectra of the compounds with cis-, gosh-, and trans-orientations of vinyl
groups are analyzed based on the ab initio calculations. It is concluded that the experimental data available in the literature
agree with the hypothesis that divinylacetylene exists as cis- and trans-isomers.
Translated fromZhumal Strukturnoi Khimii, Vol. 39, No. 4, pp. 610–617, July–August, 1998. 相似文献
18.
T. V. Kharlamova 《Chemistry of Natural Compounds》2007,43(4):391-394
The alkylation of 1,6,8-trihydroxy-3-methylanthraquinone (frangula-emodin) by α-bromoalkylmethylketones was investigated. Hydroxyls in the 1-and 8-positions of the β-derivatives were O-acylated. The compositions and structures of the prepared compounds were confirmed by elemental analysis and UV, IR, PMR,
and 13C NMR spectroscopy.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 324–326, July–August, 2007. 相似文献
19.
To evaluate the reactivity of new difluroroaromatic compounds in nucleophilic substitution, the positive charges on carbon
atoms of C−F bonds were calculated using the quantum-chemical semiempirical PM3 method. A correlation between the charges
calculated and the chemical shifts in the19F NMR spectra was established.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 623–625, April, 1998. 相似文献
20.
Chlorosulfonyl-containing naphthol azo compounds were prepared by reaction of the corresponding sulfonate-containing naphthol
azo dyes with thionyl chloride in the presence of a catalytic quantity of N,N-dimethylformamide and various solvents. The yields and reaction selectivity of chlorosulfonyl-containing naphthol azo compounds
were discussed according to the properties of solvents. It was demonstrated that high chemical selectivity and high yield
were achieved by using benzene, toluene or thionyl chloride as solvent. Additionally, on account of unstable properties of
sulfonyl chloride compounds in MS and 1H-NMR analyses, a new analytical method using stable sulfonamide is put forward to verify the chemical structures of the corresponding
sulfonyl chloride compounds indirectly.
__________
Translated from Journal of Dalian University of Technology, 2008, 48(1): 26–32 相似文献