The synthesis of the title compound ([C28H22ClN2]·ClO4) has been synthesized and its structure was determined by X-ray diffraction. The compound belongs to the monoclinic system, space group P21/n with a = 15.113...The synthesis of the title compound ([C28H22ClN2]·ClO4) has been synthesized and its structure was determined by X-ray diffraction. The compound belongs to the monoclinic system, space group P21/n with a = 15.113(5), b = 8.616(3), c = 19.556(7) ?, β = 92.562(7)°, Z = 4, V = 2544(2) ?3, Mr = 521.38, Dc = 1.361 g/cm3, F(000) = 1080, μ = 0.293 mm-1, the final R = 0.0580 and wR = 0.0788 (I > 2σ(I)). The structure was solved by direct methods and refined by full-matrix least-squares techniques. X-ray analysis revealed that there exist four ring planes of 10H-indolium, pyridinium, p-chlorophenyl and indolyl in the molecule, of which the pyridinium ring forms a conjugated system with the p-chlorophenyl plane. According to the molecular structure of the title compound, it is presumed that the synthetic reaction may undergo the processes of C-addition, cyclization and aromatization.展开更多
We describe the current plans for a spectroscopic survey of millions of stars in the Milky Way galaxy using the Guo Shou Jing Telescope (GSJT, formerly calledthe Large sky Area Multi-Object fiber Spectroscopic Telesc...We describe the current plans for a spectroscopic survey of millions of stars in the Milky Way galaxy using the Guo Shou Jing Telescope (GSJT, formerly calledthe Large sky Area Multi-Object fiber Spectroscopic Telescope -- LAMOST). The survey will obtain spectra for 2.5 million stars brighter than r 〈 19 during dark/grey time, and 5 million stars brighter than r 〈 17 or J 〈 16 on nights that are moonlit or have low transparency. The survey will begin in the fall of 2012, and will run for at least four years. The telescope's design constrains the optimal declination range for observations to 10~ 〈 di 〈 50~, and site conditions lead to an emphasis on stars in the direction of the Galactic anticenter. The survey is divided into three parts with different target selection strategies: disk, anticenter, and spheroid. The resulting dataset will be used to study the merger history of the Milky Way, the substructure and evolution of the disks, the nature of the first generation of stars through identification of the lowest metallicity stars, and star formation through study of open clusters and OB associations. Detailed design of the LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) survey will be completed in summer 2012, after a review of the results of the pilot survey.展开更多
文摘The synthesis of the title compound ([C28H22ClN2]·ClO4) has been synthesized and its structure was determined by X-ray diffraction. The compound belongs to the monoclinic system, space group P21/n with a = 15.113(5), b = 8.616(3), c = 19.556(7) ?, β = 92.562(7)°, Z = 4, V = 2544(2) ?3, Mr = 521.38, Dc = 1.361 g/cm3, F(000) = 1080, μ = 0.293 mm-1, the final R = 0.0580 and wR = 0.0788 (I > 2σ(I)). The structure was solved by direct methods and refined by full-matrix least-squares techniques. X-ray analysis revealed that there exist four ring planes of 10H-indolium, pyridinium, p-chlorophenyl and indolyl in the molecule, of which the pyridinium ring forms a conjugated system with the p-chlorophenyl plane. According to the molecular structure of the title compound, it is presumed that the synthetic reaction may undergo the processes of C-addition, cyclization and aromatization.
基金partially supported by the National Natural Science Foundation of China (Grant Nos. 10573022, 10973015, 11061120454and 11243003)the US National Science Foundation through grant AST-09-37523
文摘We describe the current plans for a spectroscopic survey of millions of stars in the Milky Way galaxy using the Guo Shou Jing Telescope (GSJT, formerly calledthe Large sky Area Multi-Object fiber Spectroscopic Telescope -- LAMOST). The survey will obtain spectra for 2.5 million stars brighter than r 〈 19 during dark/grey time, and 5 million stars brighter than r 〈 17 or J 〈 16 on nights that are moonlit or have low transparency. The survey will begin in the fall of 2012, and will run for at least four years. The telescope's design constrains the optimal declination range for observations to 10~ 〈 di 〈 50~, and site conditions lead to an emphasis on stars in the direction of the Galactic anticenter. The survey is divided into three parts with different target selection strategies: disk, anticenter, and spheroid. The resulting dataset will be used to study the merger history of the Milky Way, the substructure and evolution of the disks, the nature of the first generation of stars through identification of the lowest metallicity stars, and star formation through study of open clusters and OB associations. Detailed design of the LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) survey will be completed in summer 2012, after a review of the results of the pilot survey.