共查询到20条相似文献,搜索用时 15 毫秒
1.
E. P. D’yachkov D. V. Makaev L. O. Khoroshavin P. N. D’yachkov 《Russian Journal of Inorganic Chemistry》2017,62(7):931-934
The electronic structure of hexagonal TiO2 nanotubes doped with 3d transition metals from Sc to Zn was calculated by the linearized augmented cylindrical wave method. The calculated densities of states demonstrate that the substitution of Sc, V, Co, Cu, or Fe atoms for a part of Ti atoms leads to the decrease in the band gap width of the material from 4 to 2 eV. Such nanotubes are promising materials for creation of electrodes for electrochemical photolysis of water. 相似文献
2.
Coordinational compounds of 3<Emphasis Type="Italic">d</Emphasis>-metal phthalates with nicotinamide
T. V. Koksharova I. S. Gritsenko I. V. Stoyanova S. E. Samburskii 《Russian Journal of General Chemistry》2009,79(6):1175-1182
Complexes of iron(II), cobalt(II), nickel(II), copper(II), and zinc with nicotinamide were synthesized. The compounds obtained were characterized by means of chemical analysis, conductometry, thermogravimetry, and by means of the IR and the diffuse reflection spectroscopy. 相似文献
3.
The structure and properties of the monocarbides ScC, TiC, VC, CrC, MnC, FeC, CoC, NiC, CuC, ZnC and their negatively and positively charged ions together with 3 d-metal monoxide cations are calculated by density functional theory (DFT) and hybrid DFT methods. In addition to the spectroscopic constants, the computed properties include the electron affinities, ionization energies, and dissociation energies. These results along with our previous results for the neutral and negatively charged 3 d-metal monoxides allow a detailed comparison of similarity and differences in the bonding of the metal oxides and carbides. These results are compared with results obtained using other theoretical approaches and with experiment. Chemical bonding, analyzed using the natural bond orbital scheme, was found to be rather different in the 3 d-metal monocarbides and monoxides. 相似文献
4.
T. M. Ivanova A. V. Shchukarev R. V. Linko M. A. Kiskin A. A. Sidorov V. M. Novotortsev I. L. Eremenko 《Russian Journal of Inorganic Chemistry》2011,56(1):104-109
The electronic structure and magnetic states in the heterometallic hexanuclear complex Mn4IIFe2III (μ4-O)2(Piv)10 · MeCN4 have been studied by X-ray photoelectron spectroscopy (XPS). The substitution of two Mn atoms for two Fe atoms in the hexanuclear
complex was found to have an effect on the patterns of iron and manganese X-ray photoelectron spectra. XPS data are evidence
of the high-spin paramagnetic state of MnII and FeIII atoms, as well as of the ligand-metal charge transfer upon complex formation. In the heteroatomic complex, the degree of
bond covalence increased for both the manganese and iron atoms. The results obtained are in good agreement with X-ray diffraction
data. 相似文献
5.
N. N. Makhmudiyarova G. M. Kiyamutdinova A. G. Ibragimov U. M. Dzhemilev 《Russian Journal of Organic Chemistry》2017,53(4):604-609
An efficient method has been developed for the synthesis of 7,16,25-triaryl-7,8,16,17,25,26-hexahydro-6H,15H,24H-tribenzo[f,m,t][1,5,8,12,15,19,3,10,17]hexaoxatriazacyclohenicosines, 3,8-diaryl-2,3,4,7,8,9-hexahydrobenzo[1,2-e:4,3-e′]bis[1,3]oxazines, 3,9-bis(chlorophenyl)-3,4,9,10-tetrahydro-2H,8H-benzo[1,2-e:3,4-e′]bis[1,3]oxazines, and 2,9-bis(chlorophenyl)-1,2,3,8,9,10-hexahydrobenzo[1,2-e:6,5-e′]bis-[1,3]oxazines via cycloaminomethylation of pyrocatechol, resorcinol, and hydroquinone with N,N-bis(methoxymethyl) anilines in the presence of samarium catalysts. 相似文献
6.
Modern quantum-chemical and photophysical methods have been used to study the structure of the frontier molecular orbitals and the nature of ligand-to-metal charge transfer (LMCT) transitions of structurally complex d 0-metallocenes. It has been shown that such metal complexes with carboranyl ligands have emissive LMCT states with preferential charge transfer from aromatic π-ligands to the metal and a large electric dipole moment. The electronic excitation and absorption spectra were simulated for the first time, and dipole moments of metal complexes containing metal–carbon σ- and π-bonds were estimated, which is of fundamental importance for the development of molecular photonics. 相似文献
7.
H. Y. Zhang H. Li G. Liu T. T. Liu F. Yue J. D. Wang 《Russian Journal of Coordination Chemistry》2011,37(11):839-844
One-pot reaction containing Zn(NO3)2, Cd(NO3)2, NH4SCN, and 4-amino-1,2,4-triazole (Atrz) proceeded by refluxing for different periods and gave different products. When the
mixture was refluxed for 1 h, the product was a 1D chain polymer [Cd(Atrz)2(SCN)2]
n
. However, when the refluxing time was increased to 3 h, a novel 3D 3d-3d heterometallic framework complex [Cd2.84Zn2.16(Atrz)6(SCN)10] · 4H2O (I) with 66 topology was obtained. The fluorescent property of I in the solid state was discussed. 相似文献
8.
X. J. Kong C. Guo G. X. Liu Y. Wang S. Nishihara 《Russian Journal of Coordination Chemistry》2012,38(2):134-139
A 3d-3d heterometallic coordination polymer, M(Bpp)(BDC) (I) (M = Co and Zn, Bpp = 1,3-bis(4-pyridyl)propane and H2BDC = 1,4-benzenedicarboxylic acid), has been prepared by hydrothermal synthesis and structurally characterized by IR, elemental
analysis, and single-crystal X-ray diffraction. The Co(II) and Zn(II) ions in I are located indisorder with a molar ratio of 0.35: 0.65. Complex I crystallizes in the orthorhombic space group Pbca and displays a two-dimensional 2-fold interpenetrated structure with (4,4) topology. The coexistence of two metal ions in
the structure makes them more thermally stable than thepreviously reported homometallic polymers of Co(II) or Zn(II) ions.
Complex I exhibits weaker antiferromagnetism than the pure Co(II) complex owing to the incorporation of Zn(II). 相似文献
9.
H. Y. Zhang H. Li G. Liu T. T. Liu F. Yue J. D. Wang 《Russian Journal of Coordination Chemistry》2011,37(6):411-416
One-pot reaction containing Zn(NO3)2, Cd(NO3)2, NH4SCN, and 4-amino-1,2,4-triazole (Atrz) was proceeded by refluxing for different periods and gave different products. When
the mixture was refluxed for 1 h, the product was a 1D chain polymer [Cd(Atrz)2(SCN)2]
n
. However, when the refluxing time was increased to 3 h, a novel 3D 3d-3d heterometallic framework complex [Cd2.84Zn2.16(Atrz)6(SCN)10] · 4H2O (I) with 66 topology was obtained. The photoluminescence property of I in the solid state was discussed.. 相似文献
10.
G. V. Novikov L. N. Kulikova O. Yu. Bogdanova G. I. Sychkova O. M. Dara I. G. Lugovskaya 《Russian Journal of Inorganic Chemistry》2009,54(2):180-190
Layered compounds based on hydrous manganese dioxide (hereafter, Mn-phases) saturated with s-metal (Ba2+), p-metal (Pb2+), and d-metal (Mn2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+) cations, analogues of manganese minerals of oceanic ferromanganese formations (vernadite, birnessite, buserite-I, and asbolan), were prepared at 4–6°C. All Mn-phases have poorly ordered structures. The sorption properties of phase compounds were studied in relation to alkali-metal (Na+ and K+) and other s-, p-, and d-metal cations. The exchange capacities of Mn-phases for alkali cations are very low, within 0.02–0.10 mg-equiv/g; for the other cations, the exchange capacities are 0.13–4.20 mg-equiv/g. The sorption of divalent metal cations depends on the phase and chemical composition of the Mn-phase. 相似文献
11.
The 5p-4d emission spectrum, obtained during cascade de-excitation of the initial deep 3d vacancy in the Xe atom, was calculated by directly constructing a decay tree in a stepwise manner. The cascade decay tree was constructed with allowance for all radiative and nonradiative channels of decay for the initial and all intermediate ionic configurations of the cascade. The probabilities of branching and transition energies were calculated in a one-electron approximation with averaging over configurations. The 5p-4d cascade emission spectrum has a complex structure with many components, which reflects the transitions from the wide variety of the many-hole intermediate configurations generated by the cascade. The calculated data agree well with the experiment. 相似文献
12.
Group-theoretical and quantum-chemical investigations of the spectrum of low-lying excited states have been performed by the ROHF and FCI-RAS (Full CI in Restricted Active Space) methods for 3d metal endofullerenes (MEFs) M@C60 (M =Mn, Cr, and Fe) in different charged states. The major purpose of this study is quantum-chemical verification of the anomalous (“non-Bethe’s”) character of splitting of the d N atomic states in an electrostatic field with icosahedral symmetry, predicted previously within the theory of integral invariants theory. The interrelation between the integral invariants theory and the quantumchemical methods applied in this work is considered in detail. Our calculations suggest that the d N atomic states in the icosahedral field generated by fullerene C60 (I h ) on a metal atom (ion) remain non-split for different charged states of the metal and C60. Reasons for this phenomenon and other possible approaches to verification of the prediction are discussed. It is demonstrated that the d N states of the encapsulated metal are split in icosahedral 3d MEFs only under very strong compression of these structures. 相似文献
13.
Chanukorn Tabtimsai Thanawat Somtua Tawit Motongsri Banchob Wanno 《Structural chemistry》2018,29(1):147-157
The binding of 3d (Sc, Ti, V), 4d (Y, Zr, Nb), and 5d (La, Hf, Ta) transition metals on graphene nanosheet (TM–GNS) with hydrogen-terminated edges and the adsorption of H2CO and HCN molecules on the pristine and TM-doped GNSs were theoretically studied using a density functional theory method. The calculation showed that all TM atoms had strong binding with GNS, in which the Ta atom displayed the strongest interaction with GNS. The H2CO and HCN molecules showed much stronger adsorption on the TM–GNSs than that on the pristine GNS. The H2CO showed stronger interactions with TM–GNSs than that of HCN, in which the Ta-doping displayed the strongest interactions between the GNS and H2CO or HCN. The adsorption interactions induced dramatic changes of TM–GNS electronic properties. The results revealed that the adsorption strength and sensor ability of GNS can be greatly improved by introducing appropriate TM dopants. Therefore, TM-doped GNSs are suitable for application in H2CO and HCN storage and sensor. 相似文献
14.
I. V. Shugalei A. A. Ivanova M. A. Ilyushin I. V. Tselinskii V. V. Sokolova 《Russian Journal of General Chemistry》2009,79(1):129-133
A method is suggested for quantitative assessment of the anti-/prooxidant activity of d-metal cations by their effect of the rate of the reduction of nitrotetrazolium blue to formazan in a system generating the superoxide radical anion in the presence of reduced nicotinamide adenine dinucleotide (NADH2). The effect of the acidity of the medium on the anti/prooxidant activity of cations, as well as correlations between the ionization potentials, ionic radii, and antioxidant properties of cations are analyzed. 相似文献
15.
Properties of frontier orbitals and low-energy electronic transitions in a d 0-organometallic complex have been studied by TDDFT and DFT methods using B3LYP hybrid functional and 3-21G*, 6-31G**, SDD, CEP-121G, and DGDZVP basis sets. It has been shown that the electronic transition between frontier orbitals in the excitation and absorption spectra is associated with charge transfer mainly from π-type ligands to a central metal d 0-ion. The good agreement of the data (the shape and band position of the spectra of electronic absorption and excitation, energy of electronic transitions, and strength of the harmonic oscillator) of quantum-chemical and photophysical studies is demonstrated. 相似文献
16.
G. S. Kuanysheva K. U. Dzhamansarieva G. Zh. Sdikova 《Russian Journal of Inorganic Chemistry》2007,52(9):1359-1362
The mean atomic Gibbs energies of formation of (Δ f ? at 0 ) of s-, p-, and d-element diphosphates have been calculated using ion increments of the Gibbs energy (Δ f G 0). The diphosphate hydrolysis kinetics is considered, and a correlation between the Δ f ? at 0 values and the hydrolysis rate constants is presented. 相似文献
17.
T. F. Ibragimov M. G. Levkovich V. A. Saprykina Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2010,46(5):767-770
N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The
point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated. 相似文献
18.
A. M. Makarevich B. G. Kimel’ N. P. Kuz’mina 《Russian Journal of Inorganic Chemistry》2007,52(11):1775-1780
The composition of aqueous solutions of the heterometallic chelates MLnDTPA and Ln2M3(EDTA)3 (H5DTPA = diethylenetriaminepentaacetic acid; H4EDTA = ethylenediaminetetraacetic acid; Ln = Eu, La; M = Ni, Mn) and the monometallic chelates H3Ni(DTPA), HNi2(DTPA), H2La(DTPA), and H2Eu(DTPA) was studied by electrospray mass spectrometry (ESIMS). The mass spectra indicate that there is equilibrium between chelated rare-earth and 3d-metal ions in the aqueous solution of the heterometallic chelates. Both monometallic and bimetallic diethylenetriaminepentaacetates are observed for the 3d elements. The intensity ratio of the chelated rare-earth and 3d-metal ions in the aqueous solutions of the heterometallic complexes is in agreement with the ratio of the stability constants of the respective monometallic chelates. 相似文献
19.
G. S. Kuanysheva K. U. Dzhamansarieva G. Zh. Sdikova 《Russian Journal of Inorganic Chemistry》2007,52(9):1363-1364
The hydrolysis kinetics of the anion in 3d-element cyclotetraphosphates is considered. The thermodynamic functions of formation (Δ f H 0, Δ f G 0, and Δ f ? at 0 ) of the cyclotetraphosphates are calculated using the ion increment method. A linear correlation is established between and log K Δ f ? at 0 for these compounds. 相似文献
20.
Glucose 2-oxidase (pyranose oxidase, pyranose:oxygen-2-oxidoreductase, EC 1.1.3.10) from Coriolus versicolor catalyses the oxidation of d-glucose at carbon 2 in the presence of molecular O2 producing d-glucosone (2-keto-glucose and d-arabino-2-hexosulose) and H2O2. It was used to convert d-glucose into d-glucosone at moderate pressures (i.e. up to 150 bar) with compressed air in a modified commercial batch reactor. Several
parameters affecting biocatalysis at moderate pressures were investigated as follows: pressure, [enzyme], [glucose], pH, temperature,
nature of fluid and the presence of catalase. Glucose 2-oxidase was purified by immobilized metal affinity chromatography
on epoxy-activated Sepharose 6B-IDA-Cu(II) column at pH 6.0. The rate of bioconversion of d-glucose increased with the pressure since an increase in the pressure with compressed air resulted in higher rates of conversion.
On the other hand, the presence of catalase increased the rate of reaction which strongly suggests that H2O2 acted as inhibitor for this reaction. The rate of bioconversion of d-glucose by glucose 2-oxidase in the presence of either nitrogen or supercritical CO2 at 110 bar was very low compared with the use of compressed air at the same pressure. The optimum temperature (55°C) and
pH (5.0) of d-glucose bioconversion as well as kinetic parameters for this enzyme were determined under moderate pressure. The activation
energy (E
a) was 32.08 kJ mol−1 and kinetic parameters (V
max, K
m, K
cat and K
cat/K
m) for this bioconversion were 8.8 U mg−1 protein, 2.95 mM, 30.81 s−1 and 10,444.06 s−1 M−1, respectively. The biomass of C. versicolor as well as the cell-free extract containing glucose 2-oxidase activity were also useful for bioconversion of d-glucose at moderate pressures. The enzyme was apparently stable at moderate pressures since such pressures did not affect
significantly the enzyme activity. 相似文献