The molecule with Th symmetry is rare.A dodecahedrane-like molecule C12H12B8 with uncommon Th symmetry has been reported here.Density functional calculations and minimization techniques have been employed to character...The molecule with Th symmetry is rare.A dodecahedrane-like molecule C12H12B8 with uncommon Th symmetry has been reported here.Density functional calculations and minimization techniques have been employed to characterize its structural and electronic properties.Its geometry,electronic properties,vibrational frequencies and heat of formation have been calculated at the B3LYP/6-311＋G（d,p） level of theory.The absence of imaginary vibrational frequency confirms that it corresponds to true minimum on the potential energy hypersurface.Its vibrational bands in the IR intensity have been discussed and compared with future experimental identification.At the B3LYP/6-311＋G（d,p） level,the heat of formation has been calculated to be 720.9 kJ mol^-1 using the isodesmic reaction.According to this value,it is a potential high energy density molecule.展开更多
Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good ...Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good choice to compute MKS charges for reproducing the experimental values of molecular dipole moments. Root mean square deviation of computed dipole moments for 21 small polar molecules is about 0.1969 D.展开更多
The boron rings containing planar octacoordinate transition metals, D8h FeB82-, CoB8- and CoB83+, C2v FeB8, D2h CoB8+ and CoB8, are optimized with all real vibrational frequencies at the B3LYP/6-311+G* level of the th...The boron rings containing planar octacoordinate transition metals, D8h FeB82-, CoB8- and CoB83+, C2v FeB8, D2h CoB8+ and CoB8, are optimized with all real vibrational frequencies at the B3LYP/6-311+G* level of the theory. The D8h FeB82- and CoB8- isomers are global minima, while D8h CoB83+ is only local minimum. The electronic structure character of these systems is revealed by natural bond orbital (NBO) analysis, showing that the boron rings containing planar octacoordinate transition metals have stability and aromaticity with six π electrons. The aromaticity is confirmed by nucleus independent chemical shifts (NICS) calculations.展开更多
基金supported by the Natural Science Foundation of Shandong Province (No. ZR2011BM022)
文摘The molecule with Th symmetry is rare.A dodecahedrane-like molecule C12H12B8 with uncommon Th symmetry has been reported here.Density functional calculations and minimization techniques have been employed to characterize its structural and electronic properties.Its geometry,electronic properties,vibrational frequencies and heat of formation have been calculated at the B3LYP/6-311＋G（d,p） level of theory.The absence of imaginary vibrational frequency confirms that it corresponds to true minimum on the potential energy hypersurface.Its vibrational bands in the IR intensity have been discussed and compared with future experimental identification.At the B3LYP/6-311＋G（d,p） level,the heat of formation has been calculated to be 720.9 kJ mol^-1 using the isodesmic reaction.According to this value,it is a potential high energy density molecule.
基金The project was supported by the National Science Foundation (29773021) Provincial Educational Foundation of Jiangsu (98KJB150001).
文摘Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good choice to compute MKS charges for reproducing the experimental values of molecular dipole moments. Root mean square deviation of computed dipole moments for 21 small polar molecules is about 0.1969 D.
基金Supported by the specialized research fund for the doctoral program of higher education (20060007030)
文摘The boron rings containing planar octacoordinate transition metals, D8h FeB82-, CoB8- and CoB83+, C2v FeB8, D2h CoB8+ and CoB8, are optimized with all real vibrational frequencies at the B3LYP/6-311+G* level of the theory. The D8h FeB82- and CoB8- isomers are global minima, while D8h CoB83+ is only local minimum. The electronic structure character of these systems is revealed by natural bond orbital (NBO) analysis, showing that the boron rings containing planar octacoordinate transition metals have stability and aromaticity with six π electrons. The aromaticity is confirmed by nucleus independent chemical shifts (NICS) calculations.
