Using geometry optimization and DFT method at the B3LYP/6-31G* level for C20H10, an equilibrium geometry is identified to have the form of polyhedral hydrocarbon with five carbon-carbon single bonds linking two pentap...Using geometry optimization and DFT method at the B3LYP/6-31G* level for C20H10, an equilibrium geometry is identified to have the form of polyhedral hydrocarbon with five carbon-carbon single bonds linking two pentaprismane cages. Thus, C20H10 is a tri-cage molecule with three pentaprismane cages. Vibrational frequencies and infrared spectrum are computed at the same level. The heat of formation for this molecule has also been estimated in this paper.展开更多
The crystal structure of the title compound, diethyl 4,5-di（thienyl）-3,6-bis（trime- thylsilyl）phthalate （C26H3404S2Si2, Mr = 530.83）, has been determined by single-crystal X-ray diffraction. The crystal belongs ...The crystal structure of the title compound, diethyl 4,5-di（thienyl）-3,6-bis（trime- thylsilyl）phthalate （C26H3404S2Si2, Mr = 530.83）, has been determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pccn with a = 43.008（5）, b = 10.9000（12）, c = 11.9357（14） A, V= 5595.3（11） A3, Z = 8, F（000） = 2256, Dc= 1.260 mg/m3, p = 0.305 mm-1, T = 113（2） K, S = 1.090, R = 0.0413 and wR = 0.0969 for 5952 observed reflections with 1 〉 2o（/）. The benzene ring system is planar and makes dihedral angles of 63.7（2） and 72.5（4） with the two thienyl rings A （C（23）-C（26）, S（2）） and B （C（19）-C（22）, S（1））, respectively. The UV-vis absorption and fluorescence of the title compound were discussed. The molecular structure of the title compound has been optimized using DFT method at the B3LYP/6-31G（d） level. The computational results showed that the optimized geometer parameters are consistent well with the experiment data. The vertical ionization potential, vertical electron affinity and frontier orbitals were also discussed.展开更多
Two C16H12O4 isomers of derivatives of pagodane were firstly reported and studied by using DFT method. Geometries, energies, and vibrational frequencies have been calculated for the two C16H12O4 isomers with pagodane-...Two C16H12O4 isomers of derivatives of pagodane were firstly reported and studied by using DFT method. Geometries, energies, and vibrational frequencies have been calculated for the two C16H12O4 isomers with pagodane-like structures at the B3LYP/6-31G^＊＊ level of theory. Symmetries of isomer 1 and 2 are D2h and D2d, respectively. Heats of formation for the two C16H12O4 isomers have been estimated in this paper. According to the heats of formation, the two C16H12O4 isomers are more stable than pagodane. Heats of formation as well as the vibrational analysis indicate that the two C16H12O4 isomers enjoy sufficient stability to allow for the experimental preparation.展开更多
Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ level.Isomers 1 and 2 are of D2h and D2d symmetry, res...Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ level.Isomers 1 and 2 are of D2h and D2d symmetry, respectively. Heats of formation for the two C4N12O4 isomers have been estimated in this paper, indicating they would be reasonable candidates for high energy density materials.展开更多
Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LY...Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LYP/6-31G* level. All molecular species involved in the four reaction steps have been fully optimized and the structural parameters are provided, and the micro process of reaction was also investigated. The catalyst-alkoxyborane adduct formed in step III exhibits a B-O-B-N tetra-atomic ring. Reaction coordination calculations show that BH3 can react with 3-morpholin-4-yl-1-phenyl-1-propanone spontaneously, resulting in the need of 2 mol BH3 in the reaction.展开更多
DFT/6-31G^＊ calculations were applied to study the direct aldol reaction between acetone and 4-nitrobenzaldehyde catalyzed by （S）-proline. Four transition states associated with the stereo-controlling step, corresp...DFT/6-31G^＊ calculations were applied to study the direct aldol reaction between acetone and 4-nitrobenzaldehyde catalyzed by （S）-proline. Four transition states associated with the stereo-controlling step, corresponding to syn and anti arrangements of methylene moiety related to the carboxylic acid group in enamine intermediate and re and si attacks to the aldehyde carbonyl carbon have been obtained. The solvent effect of DMSO was investigated with polarized continuum model. The computed energies of transition states reveal the stereo-selectivity of the reaction.展开更多
The molecule with Th symmetry is rare. Two C60-1ike molecules C48N12 and C48B12 with rare Th symmetry have been reported here, which is an approach to seek for the molecule with rare Th symmetry. Their structural, ele...The molecule with Th symmetry is rare. Two C60-1ike molecules C48N12 and C48B12 with rare Th symmetry have been reported here, which is an approach to seek for the molecule with rare Th symmetry. Their structural, electronic, vibrational, NMR, and thermodynamic properties have been calculated at the B3LYP/6-31G（d） level of theory. Vibrational modes have been assigned according to their symmetry. They all have 73 independent vibrational modes： 22 IR-active modes with Tu symmetry and 37 Raman-active modes with Ag, Eg and Tg symmetry, respectively. The heats of formation have been calculated using isodesmic reactions, and the values of C48N12 and C48B12 are 3812.0 and 3423.8 kJ mo1-1, respectively. According to the estimated band gaps for their fcc solid, they are all semiconducting materials, like C60, especially C48B12-based fcc solid.展开更多
Using geometry optimization and DFT method at the B3LYP/6-31G* level for C15H10, an equilibrium geometry was identified to have bilayer pentaprismane formed by two pentaprismane cages sharing the same pentagon. The vi...Using geometry optimization and DFT method at the B3LYP/6-31G* level for C15H10, an equilibrium geometry was identified to have bilayer pentaprismane formed by two pentaprismane cages sharing the same pentagon. The vibrational frequencies and infrared spectrum were computed at the same level, and the heat of formation was also estimated.展开更多
The molecule with Th symmetry is rare. A novel C60-1ike molecule C48O12 with rare Th symmetry has been studied at the B3LYP/6-31G（d） level of theory. Its structural, electronic, vibrational, NMR, and thermodynamic p...The molecule with Th symmetry is rare. A novel C60-1ike molecule C48O12 with rare Th symmetry has been studied at the B3LYP/6-31G（d） level of theory. Its structural, electronic, vibrational, NMR, and thermodynamic properties have been calculated at the B3LYP/6-31G（d） level of theory. Vibrational modes have been assigned according to their symmetry. There are 73 independent vibrational modes： 22 IR-active modes with Tu symmetry and 37 Raman-active modes with Ag, Eg and Tg symmetry, respectively. The heat of formation has been calculated by using isodesmic reactions, 765.7 kJ mol-1. According to the heat of formation and the HOMO-LUMO gap, C48O12 with rare Th symmetry is more stable than C6o.展开更多
基金This work was supported by the Natural Science Foundation of Shandong Province (Y2002G11)
文摘Using geometry optimization and DFT method at the B3LYP/6-31G* level for C20H10, an equilibrium geometry is identified to have the form of polyhedral hydrocarbon with five carbon-carbon single bonds linking two pentaprismane cages. Thus, C20H10 is a tri-cage molecule with three pentaprismane cages. Vibrational frequencies and infrared spectrum are computed at the same level. The heat of formation for this molecule has also been estimated in this paper.
基金supported by the Program for Innovative Research Team of Nanchang University, ChinaOpen Foundation of CAS Key Laboratory ofOrganic Solid of China+1 种基金the Natural Science Foundation of Education Department of Jiangxi Province, Chinathe Foundation of TrainingAcademic and Technical Header for Main Majors of Jiangxi Province, China~~
基金supported by the National Natural Science Foundation of China(No.21102099)
文摘The crystal structure of the title compound, diethyl 4,5-di（thienyl）-3,6-bis（trime- thylsilyl）phthalate （C26H3404S2Si2, Mr = 530.83）, has been determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pccn with a = 43.008（5）, b = 10.9000（12）, c = 11.9357（14） A, V= 5595.3（11） A3, Z = 8, F（000） = 2256, Dc= 1.260 mg/m3, p = 0.305 mm-1, T = 113（2） K, S = 1.090, R = 0.0413 and wR = 0.0969 for 5952 observed reflections with 1 〉 2o（/）. The benzene ring system is planar and makes dihedral angles of 63.7（2） and 72.5（4） with the two thienyl rings A （C（23）-C（26）, S（2）） and B （C（19）-C（22）, S（1））, respectively. The UV-vis absorption and fluorescence of the title compound were discussed. The molecular structure of the title compound has been optimized using DFT method at the B3LYP/6-31G（d） level. The computational results showed that the optimized geometer parameters are consistent well with the experiment data. The vertical ionization potential, vertical electron affinity and frontier orbitals were also discussed.
基金This work was supported by the Natural Science Foundation of Shandong Province (Y2002G11)
文摘Two C16H12O4 isomers of derivatives of pagodane were firstly reported and studied by using DFT method. Geometries, energies, and vibrational frequencies have been calculated for the two C16H12O4 isomers with pagodane-like structures at the B3LYP/6-31G^＊＊ level of theory. Symmetries of isomer 1 and 2 are D2h and D2d, respectively. Heats of formation for the two C16H12O4 isomers have been estimated in this paper. According to the heats of formation, the two C16H12O4 isomers are more stable than pagodane. Heats of formation as well as the vibrational analysis indicate that the two C16H12O4 isomers enjoy sufficient stability to allow for the experimental preparation.
基金This work was supported by the Natural Science Foundation of Shandong Province (Y2002G11)
文摘Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ level.Isomers 1 and 2 are of D2h and D2d symmetry, respectively. Heats of formation for the two C4N12O4 isomers have been estimated in this paper, indicating they would be reasonable candidates for high energy density materials.
基金Project supported by the Research Foundation of Suzhou University (Q3109306)
文摘Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LYP/6-31G* level. All molecular species involved in the four reaction steps have been fully optimized and the structural parameters are provided, and the micro process of reaction was also investigated. The catalyst-alkoxyborane adduct formed in step III exhibits a B-O-B-N tetra-atomic ring. Reaction coordination calculations show that BH3 can react with 3-morpholin-4-yl-1-phenyl-1-propanone spontaneously, resulting in the need of 2 mol BH3 in the reaction.
基金This project was supported by the Research Foundation of Key Laboratory of Organic Synthesis of Jiangsu Province (No. JSK010)
文摘DFT/6-31G^＊ calculations were applied to study the direct aldol reaction between acetone and 4-nitrobenzaldehyde catalyzed by （S）-proline. Four transition states associated with the stereo-controlling step, corresponding to syn and anti arrangements of methylene moiety related to the carboxylic acid group in enamine intermediate and re and si attacks to the aldehyde carbonyl carbon have been obtained. The solvent effect of DMSO was investigated with polarized continuum model. The computed energies of transition states reveal the stereo-selectivity of the reaction.
基金supported by the Natural Science Foundation of Shandong Province (No. ZR2011BM022)
文摘The molecule with Th symmetry is rare. Two C60-1ike molecules C48N12 and C48B12 with rare Th symmetry have been reported here, which is an approach to seek for the molecule with rare Th symmetry. Their structural, electronic, vibrational, NMR, and thermodynamic properties have been calculated at the B3LYP/6-31G（d） level of theory. Vibrational modes have been assigned according to their symmetry. They all have 73 independent vibrational modes： 22 IR-active modes with Tu symmetry and 37 Raman-active modes with Ag, Eg and Tg symmetry, respectively. The heats of formation have been calculated using isodesmic reactions, and the values of C48N12 and C48B12 are 3812.0 and 3423.8 kJ mo1-1, respectively. According to the estimated band gaps for their fcc solid, they are all semiconducting materials, like C60, especially C48B12-based fcc solid.
基金This work was supported by the Natural Science Foundation of Shandong Province (Y2002G11)
文摘Using geometry optimization and DFT method at the B3LYP/6-31G* level for C15H10, an equilibrium geometry was identified to have bilayer pentaprismane formed by two pentaprismane cages sharing the same pentagon. The vibrational frequencies and infrared spectrum were computed at the same level, and the heat of formation was also estimated.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2011BM022)
文摘The molecule with Th symmetry is rare. A novel C60-1ike molecule C48O12 with rare Th symmetry has been studied at the B3LYP/6-31G（d） level of theory. Its structural, electronic, vibrational, NMR, and thermodynamic properties have been calculated at the B3LYP/6-31G（d） level of theory. Vibrational modes have been assigned according to their symmetry. There are 73 independent vibrational modes： 22 IR-active modes with Tu symmetry and 37 Raman-active modes with Ag, Eg and Tg symmetry, respectively. The heat of formation has been calculated by using isodesmic reactions, 765.7 kJ mol-1. According to the heat of formation and the HOMO-LUMO gap, C48O12 with rare Th symmetry is more stable than C6o.
