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1.
K. K. Kalnin'sh D. N. Glebovskii M. E. Bedrina E. K. Roshchina 《Journal of Structural Chemistry》1992,33(5):636-643
Institute of High-Molecular-Weight Compounds, Russian Academy of Sciences. Leningrad State University Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 5, pp. 20–27, September–October, 1992. 相似文献
2.
DFT calculations with B3LYP and PBE0 functionals have been carried out to determine the structural parameters, vibrational frequencies, and quadrupole moments of double-decker heavy lanthanide phthalocyaninates Pc2Lu, (Pc2Lu)+, (Pc2Lu)–, Pc2Yb, (Pc2Yb)+, and (Pc2Yb)–. Free valence of the Pc moiety [0.5 in Pc2Lu and Pc2Yb; 1.0 in (Pc2Lu)+ and (Pc2Yb)+] is delocalized in small fractions over the carbon atoms. The Pc2Lu и Pc2Yb molecules have a high electron affinity (3.2 eV) and a low ionization potential (6.1–6.3 eV). Calculations predict formation of quadruple-decker supercomplex Yb(Pc2Lu)2 from two Pc2Lu molecules and an Yb atom via an exothermic process. The equilibrium structure of the molecules and ions can be characterized by D4d point symmetry group. 相似文献
3.
Semenov S. G. Makarova M. V. Bedrina M. E. Titov A. V. 《Russian Journal of General Chemistry》2021,91(3):389-392
Russian Journal of General Chemistry - A quantum-chemical model of the minimal cluster in xenotime has been proposed taking into account the ionic-crystal medium potential. The [YO8]5–... 相似文献
4.
Sergey G. Semenov Marina E. Bedrina Vladimir A. Klemeshev 《International journal of quantum chemistry》2024,124(1):e27332
The competition between the ytterbium endo-atom and the pyridine exo-molecules as nucleophiles interacting with the electron-deficient 1H,4H-1,4-diborabuckminsterfullerene was studied using the quantum chemical DFT PBE0 method. The equilibrium structural parameters, dipole moments, IR spectra, and exothermic effects of the formation of the C58B2•Py2 adduct and the endohedral Yb@C58B2•Py2 complex were determined. The concept of the state of oxidation/reduction of an atom in a chemical compound has been clarified. The localization of the ytterbium(II) under a pair of equivalent carbon atoms bonded to boron(III) atoms is predicted. The introduction of ytterbium(II) into the adduct cavity weakens exo-bonds with pyridine molecules without changing the oxidation state of boron(III). Each nitrogen atom retains a lone electron pair, coordinated by a boron(III). The ytterbium(II) endo-atom retains 14 electrons in f states. 相似文献
5.
Makarova M. V. Semenov S. G. Bedrina M. E. Titov A. V. 《Russian Journal of General Chemistry》2019,89(1):165-168
Russian Journal of General Chemistry - A model of minimum size clusters in orthophosphates has been suggested. In the case of monazite, the cluster includes a cerium(III) cation with nine oxygen... 相似文献
6.
(U)PBE0/cc-pVDZ method is used to study the structure of C60Cl30, C60(OH)30 molecules and Fe@C60(OH)30 endocomplex. The triplet state of the endocomplex is shown to be the lowest in energy among its four states corresponding to different spin multiplicities and positions of Fe nucleus within the fullerene cavity. This state is characterized by bonding between the iron atom and one of two benzenoid cycles of the carbon cage, six internuclear Fe–C distances (208 pm), and 1s22s22p63s23p63d7.24s0.14p0.3 electron configuration of iron with spin population of 2.36. 相似文献
7.
S. G. Semenov M. E. Bedrina V. A. Klemeshev A. V. Titov 《Russian Journal of General Chemistry》2018,88(4):622-625
Structural parameters and vibrational frequencies of the clusters (Td)–Nb4O10, (C3v)-TaNb3O10, (D2d)-Nb4O 10 – , and (Cs)-TaNb3O 10 – were calculated. According to the (U)DFT/SDD calculations with BLYP, B3LYP, and PBE0 functionals magnetization of the anion (D2d)-Nb4O 10 – is distributed equally among four niobium atoms. In the anion (Cs)-TaNb3O 10 – unpaired electron presumably occupies niobium atoms. The distinction in contributions from Nb atoms in the magnetization of the tantalum-containing cluster grows with the exchange component of the DFT functional in the series of functionals BLYP < B3LYP < PBE0 < UHF. 相似文献
8.
S. G. Semenov Yu. F. Sigolaev M. E. Bedrina 《Russian Journal of General Chemistry》2009,79(12):2658-2662
The equilibrium structure of the dimer (C60)2, clusters (C60)9, and (C60)7 simulating the poly-C60 (VIII) and poly-C60 (XII), as well as their boraza analogs with bisingle nitrogen-boron bonds was determined by the quantum-chemical methods
B3LYP/6-31G and PBE0/6-31G. The boraza analogs are characterized by the positive values of calculated (B3LYP/PBE0) energies
of the interpolyhedral bonds: 10/20, 35/74, and 54/109 kcal mol−1 respectively per a pair of monomers. The PBE0 method predicts shorter bond than B3LYP, and, in accordance with calorimetric
data, positive bonding energy of the polyhedra in (C60)n. 相似文献
9.
The B3LYP/6-31G quantum chemical method is used to calculate the structural parameters of [F(PcGaF)7]-, [(PcGaF)6PcGa]+ heptamers and the (PcGaF)∞, polymer of gallium(III) monofluoride phthalocyaninate. The eclipsed (ecl.) configuration (D 4h point symmetry group) corresponds to the energy minimum of the [FGa(Pc)FGa(Pc)F]- dimer. The calculated equilibrium bond lengths in the central unit of all-ecl. heptamer (GaN 1.988 Å; GaF 1.933 Å) are similar to the bond lengths in the all-ecl. polymer (GaN 1.988 Å and GaF 1.940 Å) and to the respective single crystal X-ray diffraction parameters. 相似文献
10.
S. G. Semenov M. E. Bedrina V. A. Klemeshev M. V. Makarova 《Optics and Spectroscopy》2014,117(4):516-524
Using the DFT PBE0 quantum-chemical method, we have determined the spin populations and the free valences of atoms in (i) 3,4-dimethylenefuran; (ii) exciplex 3,4-dimethylenefuran · O2; (iii) phthalocyaninates PcCu and PcCo; (iv) cations Pc+Cu, Pc+Co, and Pc+Ni; (v) dication [PcAlOAlPc]2+; and (vi) two excited triplet diketones: fulleroid-type C58(CO)2 and cyclododeca-3,4,9,10-tetraene-1,7-dione. Free valences determine atomic contributions to the doubled variance of the many-electron spin. Unlike spin populations, they are insensitive to the choice of the component of a quasi-degenerate spin state of a chemical compound and account for the regioselectivity of the radical addition to 3,4-dimethylenefuran and the photochemical stability of Pc-containing nanosystems. In a triplet state of C12H12O2, the spin density and the free valence are localized on a single carbonyl group, whereas, in a triplet state of C58(CO)2, they are delocalized. 相似文献