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1.
Interactions and natural bond orbital analysis of cyclopropylpiperazine(cppp) and B- or Al-doped C60 fullerenes are investigated by quantum mechanical calculations. The structural and electronic properties, such as NH stretching vibrations, nuclear magnetic shielding tensors of 27Al and 11B nuclei or the energy gap are also investigated. All calculations are carried out in the gas phase and water media. Results of the bond order and the binding energy suggest that chemisorption occurs between the cppp nitrogen atom and boron or aluminum atoms of fullerenes. The Alcomplex in water is foundto have the highest binding energy. Further, AlC59…cppp complexes have a slightly higher kinetic stability and a low chemical reactivity. However, BC59…cppp works as a function-type sensor for cppp.  相似文献   

2.
The absorption feasibility of benzene molecule in the C24, Si@C24, Si-doped C24, and C20 fullerenes has been studied based on calculated electronic properties of these fullerenes using Density functional Theory (DFT). It is found that energy of benzene adsorption on C24, Si@C24, and Si-doped C24 fullerenes were in range of –2.93 and –51.19 kJ/mol with little changes in their electronic structure. The results demonstrated that the C24, Si@C24, and Si-doped C24 fullerenes cannot be employed as a chemical adsorbent or sensor for benzene. Silicon doping cannot significantly modify both the electronic properties and benzene adsorption energy of C24 fullerene. On the other hand, C20 fullerene exhibits a high sensitivity, so that the energy gap of the fullerene is changed almost 89.19% after the adsorption process. We concluded that the C20 fullerene can be employed as a reliable material for benzene detection.  相似文献   

3.
The accuracy of various computational methods (Hartree–Fock, MP2, CCSD, CAS-SCF, and several types of DFT) for predicting relative intensities in Raman spectra for C6H6, C6D6, and C6F6 was compared. The predicted relative intensities for ν1 and ν2 were compared with relative intensities measured by an FT-Raman spectrometer. While none of these methods excelled at this prediction, Hartree–Fock with a large basis set was most successful for C6H6 and C6D6, while PW91PW91 was the most successful for C6F6.  相似文献   

4.
Sorption of fullerenes C60 and C70 from o-xylene, toluene, and o-dichlorobenzene solutions under static conditions on a sorbent prepared by sublimation of graphite rods was studied. The sorption isotherms of both fullerenes at 25°C were measured.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 2, 2005, pp. 345–346.Original Russian Text Copyright © 2005 by Semenov, Arapov, Charykov, Nekrasov, Alekhin, Gerasimov, Seregin.  相似文献   

5.
(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   

6.
Sorption of fullerenes C60 and C70 from o-xylene, toluene, and dichlorobenzene solutions on NORIT-AZO carbons was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1638–1642.Original Russian Text Copyright © 2004 by Semenov, Seregin, Arapov, Charykov.  相似文献   

7.
Knudsen cell mass spectrometry was used to study ion-molecular electron exchange reactions between some trifluoromethyl derivatives of C60 fullerene. Electron affinity values were experimentally determined for C60(CF3)10 and the S 6 isomer of C60(CF3)12 and compared with the results of calculations and the data in the literature.  相似文献   

8.
The results of a quantum-chemical study of the reactivity of fullerene C60 in such reactions as polymerization (dimerization), cycloaddition, addition of valence-saturated molecules are presented. The mechanisms of these reactions are also discussed.  相似文献   

9.
The structure of (C3H6N3)4Bi2Cl10 was determined by single crystal X-ray diffraction at room temperature. It crystallizes in the orthorhombic space group Pcmn, with a = 9.430 (1) Å, b = 17.426 (3) Å, c = 19.883(5) Å, V = 3267.3 (11) Å3 and Z = 4. The structure consists of discrete binuclear [Bi2Cl10]4– anions and 3-aminopyrazolium cations. The crystal packing is governed by weak N–H···Cl hydrogen bonds, π–π and electrostatic Cl···Cl interactions. Infrared spectrum is used to gain more information on the title compound. An assignment of the observed vibration modes is reported. The crystal morphology is studied using the BFDH laws. The calculated HOMO and LUMO energies show that charge transfer occur within organic and inorganic molecules. The optical absorption of the zero-dimensional hybrid was also investigated.  相似文献   

10.
New chromatographically pure monoand hexamethanofullerenes C60 and C70 containing active allylic groups were synthesized by Bingel—Hirsch reaction. These compounds are promising for the studies of biological activity, as well as for obtaining on their basis new fullerenecontaining materials. The purity and composition of the synthesized compounds were confirmed by MALDI-TOF mass spectrometry and HPLC, their structure was established by 1H and 13C NMR spectroscopy and X-ray diffraction.  相似文献   

11.
12.
Nitroxide derivatives of C60 and C70 were obtained by [3+2] cycloaddition of 4-(4-azidophenyl)-2,2,5,5-tetramethyl-3-oxy-2,5-dihydroimidazol-1-oxyl to fullerenes. The products were isolated by TLC and studied by EPR and optical spectroscopy. Molecular rotation of the adducts was shown to slow down on successive addition of the nitroxides, rotational correlation times depending nearly linearly on the number of the nitroxides added. Investigation of photochemical stability of nitroxide derivatives of C60 and C70 in benzene-ethanol medium reveal that the dissolved oxygen quenches efficiently the excitation of nitroxide (λ = 250–400 nm). In the absence of oxygen photoexcitation converts nitroxides to diamagnetic products, presumably, hydroxylamines formed through the interaction with the solvent.  相似文献   

13.
Stable aqueous colloidal dispersions of C60 fullerene are prepared. A solvatochromic effect is revealed upon the addition of C60 solution in chlorobenzene to a water-acetone mixture.  相似文献   

14.
Fluorocyclohexa adducts C60(C4F8) n were synthesized by high-temperature reaction of fullerene C60 with 1,2-C2F4I2 or 1,4-C4F8I2 in sealed tubes. Their separation by HPLC allowed us to determine molecular structure (X-ray diffraction) of four new compounds C6(C4F8) n (n = 2, 3, 4, and 6). Structures of isomers C60(C4F8) n were discussed in terms of a concept of consecutive addition of C4F8 groups to the fullerene cage.  相似文献   

15.
Measurement of the 3Π-3Π transition of C6H+ in the gas phase near 19486 cm−1 is reported. The experiment was carried out with a supersonic slit-jet expansion discharge using cavity ringdown absorption spectroscopy. Partly resolved P lines and observation of band heads permitted a rotational contour fit. Spectroscopic constants in the ground and excited-state were determined. The density of ions being sampled is merely 2×108 cm−3. Broadening of the spectral lines indicates the excited-state lifetime to be ≈100 ps. The electronic transition of HC6H2+ at 26402 cm−1 assumed to be 1A1-X1A1 in C2v symmetry could not be rotationally resolved.  相似文献   

16.
Palladium and platinum complexes of fulleienes C60 and C70 containing the axially chiral ligand (—)-BITIANP (BITIANP is 2,2’-bis(diphenylphosphino)-3,3’-bi(benzo[b]thiophene)) and pynolidino[60]fullerene bearing a planar chiral organometallic π-complex substituent in the heteiocyclic ring were studied by circular dichroism (CD) spectroscopy.  相似文献   

17.
The copolymerization of styrene and 1-hexene with the TiCl4-Al(C6H13)3 · Mg(C6H13)2 catalytic system has been investigated. The microstructure of polymer chains, molecular-mass characteristics, and thermophysical properties of the resulting copolymers have been studied. These copolymers contain 15 to 65 mol % styrene and mostly consist of isotactic polystyrene and poly(1-hexene) blocks.  相似文献   

18.
The present research work reports the study on crystal structure, vibrational spectroscopy and thermal analysis of organic-inorganic hybrid compound (C6H5(CH2)2NH3)2CdCl4. Single crystals of bis(phenethylammonium)tetrachlorocadmate (C6H5(CH2)2NH3)2CdCl4 (PEA–Cd) were obtained by diffusion at room temperature. This compound crystallizes in the orthorhombic space group C2cb with unit cell parameters a = 7.4444(2) Å, b = 38.8965(3) Å, c = 7.3737(2) Å and Z = 4. Single crystal structure has been solved and refined to R = 0.036 and wR = 0.092. The structure consists of an extended [CdCl4]2– network and two [C6H5(CH2)2NH3]+ cations to form a two-dimensional perovskite system. The infrared (IR) spectrum of the title compound was recorded at room temperature. Differential scanning calorimetry (DSC) was used to investigate the phase transition; this compound exhibits a reversible single solid-solid phase transition.  相似文献   

19.
This research is part of a European project (namely, CODICE project), main objective of which is modelling, at a multi-scale, the evolution of the mechanical performance of non-degraded and degraded cementitious matrices. For that, a series of experiments were planned with pure synthetic tri-calcium silicate (C3S) and bi-calcium silicate (C2S) (main components of the Portland cement clinker) to obtain different calcium–silicate–hydrate (C–S–H) gel structures during their hydration. The characterization of those C–S–H gels and matrices will provide experimental parameters for the validation of the multi-scale modelling scheme proposed. In this article, a quantitative method, based on thermal analyses, has been used for the determination of the chemical composition of the C–S–H gel together with the degree of hydration and quantitative evolution of all the components of the pastes. Besides, the microstructure and type of silicate tetrahedron and mean chain length (MCL) were studied by scanning electron microscopy (SEM) and 29Si magic-angle-spinning (MAS) NMR, respectively. The main results showed that the chemical compositions for the C–S–H gels have a CaO/SiO2 M ratio almost constant of 1.7 for both C3S and C2S compounds. Small differences were found in the gel water content: the H2O/SiO2 M ratio ranged from 2.9 ± 0.2 to 2.6 ± 0.2 for the C3S (decrease) and from 2.4 ± 0.2 to 3.2 ± 0.2 for the C2S (increase). The MCL values of the C–S–H gels, determined from 29Si MAS NMR, were 3.5 and 4 silicate tetrahedron, for the hydrated C3S and C2S, respectively, remaining almost constant at all hydration periods.  相似文献   

20.
The temperature dependence of the heat capacity C p o of the [(Me3Si)7C60]2 fullerene complex was measured for the first time using precision adiabatic vacuum calorimetry over the temperature range 6.7–340 K and high-accuracy differential scanning calorimetry at 320–635 K. For the most part, the error in the C p o values was about ±0.5%. An irreversible endothermic effect caused by the splitting of the dimeric bond between fullerene fragments and the thermal decomposition of the complex was observed at 448–570 K. The thermodynamic characteristics of this transformation were calculated and analyzed. Multifractal analysis of the low-temperature (T < 50 K) heat capacity was performed, and conclusions were drawn concerning the character of the heterodynamicity of the structure. The experimental data obtained were used to calculate the standard thermodynamic functions C p o (T), H o (T) ? H o (0), S o (T) ? S o (0), and G o (T) ? H o (0) over the temperature range from T → 0 to 445 K and estimate the standard entropy of formation of the compound from simple substances at 298.15 K. The standard thermodynamic properties of [(Me3Si)7C60]2 are compared with those of the (C60)2 dimer, the [(η6-Ph2)2Cr]+[C60]?? fulleride, and the initial C60 fullerene.  相似文献   

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