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A new mixed-valence heterometal cluster Mo8VW2VIO26(C5H5N)8·2H2O has been synthesized under solvothermal conditions and characterized by X-ray single-crystal diffraction, IR, UV-vis and XPS spectroscopy. The title compound crystallizes in the triclinic system, space group P1 with a = 11.708(3), b = 12.018(4), c = 13.316(4) , a = 112.184(4), β = 97.844(4), r = 110.043(3)o, V = 1551.9(8) 3 and Z = 1 at 293(2) K. The final full-matrix least-squares refinement converged to R = 0.0414 for 4460 observed unique reflections with I 2σ(I) and w R = 0.1290 for all data(5352) and S = 1.015. In addition, its thermal stability and fluorescent property have also been investigated. 相似文献
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Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-(2-chloro-4-methyl-6-phenylpyrimidin-5-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in orthorhombic, space group Pbca with a = 19.1575(11), b = 8.2115(5), c = 21.2035(12), V = 3335.6(3)3 and Z = 4. Compound 6, 5-(2,6-dichloropyrimidin-4-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in monoclinic space group Pn with a = 8.4275(13), b = 5.4088(8), c = 13.493(2), β = 99.768(3)o, V = 4658.6(6)3 and Z = 8. Preliminary bioassay indicated that the two title compounds had good herbicidal activities. 相似文献
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The title compound tianagliflozin triacetate 1 was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic system(C27H31ClO8,Mr = 518.97),space group P21 with a = 5.3913(11),b = 16.137(2),c = 15.411(3) ,β = 94.15(3)°,V = 1337.3(5) 3,Z = 2,Dc = 1.289 g/cm3,F(000) = 548,μ = 0.190 mm-1,the final R = 0.0374 and wR = 0.0809 for 3981 observed reflections(I 2σ(I)).The structure of 1,triacetate of a highly potent SGLT2 inhibitor tianagliflozin,was unambiguously determined by single-crystal X-ray diffraction,which helped to confirm the desired β configuration at the anomeric center and the position where the deoxylation occurred.The two benzene rings in the lattice are basically orthogonal to each other.There are four intermolecular hydrogen bonds in the crystal,which helps to further stabilize the crystal. 相似文献
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The title compound(zifaxaban 2, C20H16ClN3O4 S, Mr = 429.87) was synthesized and its crystal structure was determined by single-crystal X-ray diffraction. Zifaxaban crystallizes in monoclinic, space group P21 with a = 5.7900(12), b = 13.086(3), c = 12.889(3) A, β = 100.86(3)°, V = 959.1(3) A3, Z = 2, Dc = 1.489 g/cm3, F(000) = 444, μ = 0.342 mm-1, the final R = 0.0320 and wR = 0.0640 for 2717 observed reflections(I 2σ(I)). The absolute configuration of the stereogenic center in the title compound was confirmed to be S by single-crystal X-ray diffraction. Four existing intermolecular hydrogen bonds help to stabilize the lattice and the molecule in the lattice to adopt an L-shape conformation. Zifaxaban was slightly more active than rivaroxaban 1 in in vitro assay against human FXa and therefore is promising as a drug candidate. 相似文献
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The title compound was synthesized by the reaction of 4-tert-butyl-5-(4-chlorobenzyl)-2-aminothiazole with 2,6-difluorobenzoic acid. The crystal structure of the title compound, C21H19ClF2N2OS, was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group Pbca with a = 12.6479(13), b = 13.1204(13), c = 14.1341(15), Z = 4, V = 2011.5(4)3, Mr = 420.89, Dc = 1.390 g/cm3, S = 1.023, μ = 0.326 mm-1, F(000) = 872, the final R = 0.0365 and wR = 0.0880 for 6101 observed reflections(I 2σ(I)), and R = 0.0507, wR = 0.0978 for 7779 independent reflections. X-ray crystal structure displays that the hydrogen bonding interactions observed link the molecules to form a dimeric unit. The preliminary biological test of the title compound shows good antitumor activity, with IC50 of 0.046 μmol/mL against the Hela cell line. 相似文献
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一看到标题,有人马上会问,这也太玄了吧,用珠算教学计算、教学计量听说过,能教学几何还没听说过?本文对此做以阐述。 相似文献
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有人提出:“算盘笔墨失宠,微机大显神通”。并以此作为标题,在报刊上作了报导。我认为,这种论点是很不确切的。应为:“珠算仍然得宠,它与微机各显其能”。 相似文献
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DU Kang-Kai 《结构化学》2012,31(12)
A two-dimensional lead complex, [Pb(C14N3O2H12S)(NO3)]n·nH2O, was prepared by the reaction of salicylyl-4-phenyl thiosemicarbazide and lead nitrate. The compound (C14H13N4O6PbS, Mr=572.53) crystallizes in the monoclinic space group P21/c with a=11.2984(2), b=15.6628(7), c=11.1118(2), β= 113.564(2)n, V=1802.43(10)3, Dc=2.110 g/cm3, Z=4, μ(MoKα)= 9.515 mm·1, F(000)=1084, the final R=0.0394 and wR=0.0701 for 2552 observed reflections with I > 2σ(I). The Pb(II) ion displays a distorted octahedron in which the hypothesized stereochemically active lone pair occupies the apex. The compound exhibits a two-dimensional network structure formed by the zigzag one-dimensional chains joined by two μ-O of two nitrate groups in overlapping. A large ring exists in the two-dimensional layers. The TGA of the title compound has been studied. 相似文献