At the second order Douglas–Kroll–Hess(DKH2)level,the B3 PW91 functional in conjunction with the relativistic all-electron basis set of valence triple zeta quality plus polarization functions are employed to compute...At the second order Douglas–Kroll–Hess(DKH2)level,the B3 PW91 functional in conjunction with the relativistic all-electron basis set of valence triple zeta quality plus polarization functions are employed to compute bond lengths,dissociation energies,vertical ionization potentials,and the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps of the small iridium clusters(Irn,n≤8).These results are compared with the experimental and theoretical data available in the literature.Our results confirm the theoretical predictions made by Feng et al.about the catalytic activities of the Ir4 and Ir6 clusters.From the optimized geometries,DKH2 calculations of static electric mean dipole polarizabilities and polarizability anisotropies are also carried out.It is the first time that the polarizabilities of small iridium clusters have been studied.For n≤4,the mean dipole polarizabilities per atom present an odd–even oscillatory behavior,whereas from Ir5 to Ir8,they decrease with the cluster size increasing.The dependence of the polarizability anisotropy on the structure symmetry of the iridium cluster is verified.展开更多
The reaction mechanisms of Ti（~3F） ＋ CH2C12→CH2=TiCl2 and Ti（~3F） ＋ CHC13→HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311＋＋G（d,p）level.The computational results reveale...The reaction mechanisms of Ti（~3F） ＋ CH2C12→CH2=TiCl2 and Ti（~3F） ＋ CHC13→HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311＋＋G（d,p）level.The computational results revealed that：1） Both reaction systems are initiated by Ti（~3F） atom attacking the C atom of CH2C12 and CHCl3 to activate a C-Cl bond;2） Both reaction systems were carried out via triplet reaction channels;3） CH2=TiCl2 has singlet and triplet isomers,and the singlet one is more stable;4） The HOMO of CH2=TiCl2（S） illustrates a π-bonding interaction between C and Ti;5） Only singlet HC÷TiCl3 was located,and the Mulliken atomic spin densities show that the two single electrons are mostly on the C atom.展开更多
At the Douglas-Kroll-Hess （DKI4） level, the B3PW91 functional along with the all-eleclron relativistic basis sets of valence triple and quadruple zeta qualities are used to determine the structure, stability, and el...At the Douglas-Kroll-Hess （DKI4） level, the B3PW91 functional along with the all-eleclron relativistic basis sets of valence triple and quadruple zeta qualities are used to determine the structure, stability, and electronic properties of the small silver clusters （Agn, n ≤ 7）. The results presented in this study are in good agreement with the experimental data and theoretical values obtained at a higher level of theory from the literature. Static polarizability and hyperpolarizability are also reported. It is verified that the mean dipole polarizability per atom exhibits an odd-even oscillation and that the polarizability anisotropy is directly related to the cluster shape. In this article, the first study of hyperpolarizabilities of small silver clusters is presented. Except for the monomer, the second hyperpolarizabilities of the silver clusters are significantly larger than those of the copper clusters.展开更多
基金supported by the CNPq,CAPES,and FAPES(Brazilian Agencies)
文摘At the second order Douglas–Kroll–Hess(DKH2)level,the B3 PW91 functional in conjunction with the relativistic all-electron basis set of valence triple zeta quality plus polarization functions are employed to compute bond lengths,dissociation energies,vertical ionization potentials,and the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps of the small iridium clusters(Irn,n≤8).These results are compared with the experimental and theoretical data available in the literature.Our results confirm the theoretical predictions made by Feng et al.about the catalytic activities of the Ir4 and Ir6 clusters.From the optimized geometries,DKH2 calculations of static electric mean dipole polarizabilities and polarizability anisotropies are also carried out.It is the first time that the polarizabilities of small iridium clusters have been studied.For n≤4,the mean dipole polarizabilities per atom present an odd–even oscillatory behavior,whereas from Ir5 to Ir8,they decrease with the cluster size increasing.The dependence of the polarizability anisotropy on the structure symmetry of the iridium cluster is verified.
基金financially supported by the National Natural Science Foundation of China(11174215)Natural Science Foundation of Shandong Province(ZR2012BL10)the University Science and Technology Project of Shandong Province(No.J13LD05)
文摘The reaction mechanisms of Ti（~3F） ＋ CH2C12→CH2=TiCl2 and Ti（~3F） ＋ CHC13→HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311＋＋G（d,p）level.The computational results revealed that：1） Both reaction systems are initiated by Ti（~3F） atom attacking the C atom of CH2C12 and CHCl3 to activate a C-Cl bond;2） Both reaction systems were carried out via triplet reaction channels;3） CH2=TiCl2 has singlet and triplet isomers,and the singlet one is more stable;4） The HOMO of CH2=TiCl2（S） illustrates a π-bonding interaction between C and Ti;5） Only singlet HC÷TiCl3 was located,and the Mulliken atomic spin densities show that the two single electrons are mostly on the C atom.
基金Project supported by CNPq,CAPES,and FAPES(Brazilian Agencies)
文摘At the Douglas-Kroll-Hess （DKI4） level, the B3PW91 functional along with the all-eleclron relativistic basis sets of valence triple and quadruple zeta qualities are used to determine the structure, stability, and electronic properties of the small silver clusters （Agn, n ≤ 7）. The results presented in this study are in good agreement with the experimental data and theoretical values obtained at a higher level of theory from the literature. Static polarizability and hyperpolarizability are also reported. It is verified that the mean dipole polarizability per atom exhibits an odd-even oscillation and that the polarizability anisotropy is directly related to the cluster shape. In this article, the first study of hyperpolarizabilities of small silver clusters is presented. Except for the monomer, the second hyperpolarizabilities of the silver clusters are significantly larger than those of the copper clusters.
