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1.
The chemistry of binuclear palladium(II) and platinum(II) complexes has been reviewed. This review deals with complexes derived from various classes of ligands and covers various aspects, viz. synthesis, spectroscopic and structural features and chemical reactivity, of these complexes. Applications of these complexes are briefly described in the respected sections.  相似文献   

2.
The kinetic of methanol (MeOH) and isobutanol (iBuOH) coupling to ethers has been studied. Catalytic tests were carried out in the gas phase in a fixed-bed flow microreactor, in the temperature range of 463-533 K, under atmospheric pressure, using -Al2O3 as the catalyst. The quasi-homogeneous model for the process was assumed. The reaction rates were described by simple kinetics.  相似文献   

3.
The SCF and CI wave functions for BH, obtained in calculations described in detail elsewhere [2], are compared through their electron distributions and electron moments.Taken in part from a Ph.D. thesis submitted to the University of Toronto in 1971.  相似文献   

4.
We have mapped the energy demands of the geometrical changes in donor–acceptor complexes BH3NH3 and AlCl3NH3 and in the course of their formation from their monomers. We have varied the individual geometrical parameters systematically and performed ab initio quantum chemical calculations for these structures. We investigated the energy requirements to change bond lengths and bond angles in both the monomers and complexes and the angles of torsion in the complexes. The changes of bond lengths require more energy in the monomers than in the complexes. The energies to change the acceptor bond angles in the monomers are markedly higher than in the complexes. The changes in the geometrical parameters during the complexation process are more moderate in donors than in acceptors, in agreement with prior experimental observations. The geometry versus energy variations related to the process of complexation are in agreement with the notion of relative rigidity of the donor parts and the more compliant nature of the acceptor parts as well as with the notion of competing effects in the structures of the complexes.  相似文献   

5.
The simultaneous removal of NO and soot particulates in an oxidizing atmosphere is desirable for the aftertreatment of diesel exhausts. After briefly reviewing the development of catalysts for reactions involving carbons, our recent studies on the simultaneous NO–soot removal using perovskite-related and spinel-type oxides are described.  相似文献   

6.
The reliability and usefulness of UHF methods of calculating hyperfine parameters has been examined. Comparisons with CI and SEHF methods are made.A detailed analysis of OPHF calculations for first and second row atoms has shown that various one-electron properties are accurately described by physically reasonable functions of the atomic number Z. In addition there is a strong correlation between these properties. This has led to a method whereby UHF spin densities across a row of atoms can be obtained from UHF calculations of only two atoms in that row.A strong correlation between experimental and UHF spin densities is shown to exist for atoms of the first three rows. This is used to predict experimental spin densities for atoms in these rows which have not yet been measured experimentally.  相似文献   

7.
Ab initio molecular orbital theory is used to study carbon-beryllium binding in the lowest singlet and triplet states of CH2Be. When electron correlation is included, both singlet and triplet states are significantly bound relative to the ground states of CH2 and Be fragments.  相似文献   

8.
The direct CI method, which avoids explicit calculation of the Hamiltonian matrix, is presented in a new form. The method is linked with Davidson's algorithm for iterative evaluation of the ground state eigenvector. The viability of the method is indicated by the test calculations on water which are described.  相似文献   

9.
The main characteristics of the ultraviolet absorption spectra of simple alkyl, fluorine and chlorine derivatives of silane are described. The interpretation of these spectra is discussed in relation to the respective photoelectron spectra, the Rydberg-valence-shell distinction and involvement of 3d atomic orbitals.Dedicated to Professor Dr. Hermann Hartmann on the occasion of his 65th birthday.  相似文献   

10.
Extended basis set ab initio computations are performed on HF, PNO-CI and CEPA level to determine the structure of P2H4 and the potential curve E() for rotation around the P-P axis. The structure parameters are optimized for dihedral angles of 0 ° (cis), 50 °, 80 ° (gauche or semi-eclipsed), 130 °, and 180 ° (trans). It turns out that P2H4 has a gauche equilibrium structure, a local minimum for trans which is 2.5 kJ/mol above gauche, a rather large cis barrier of 20 kJ/mol and a gauche trans barrier of 3.5 kJ/mol. The potential E() is extremely flat in the region 50 ° < < 310 °, where E() varies by less than 5 kJ/mol. Electron correlation tends to reduce the barriers but has no drastic effect on E().  相似文献   

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