（E）-1-[4-（2-hydroxy-5-methoxybenzylideneamino）-phenyl]ethanone and （E）-1-[4-（2-hydroxy-4-methoxybenzylideneamino） phenyl]ethanone：X-ray and DFT-calculated structures

The isomeric structures of(E)-1-[4-(2-hydroxy-5-methoxybenzylideneamino)-phenyl] ethanone(I) and(E)-1-[4-(2-hydroxy-4-methoxybenzylideneamino) phenyl]ethanone(Ⅱ) ,both C16H15NO3,have been determined using X-ray diffraction techniques and characterized by IR,and their molecular structures have also been optimized at the B3LYP/6-31G(d,p) level using density functional theory(DFT) . The energetic behaviors of the title compounds in solvent media have been examined using B3LYP method with the 6-31G(d,p) basis set by applying the polarizable continuum model(PCM) . The total energies of the title compounds decrease with the increasing polarity of the solvent. In addition,DFT calculations of the title compounds' molecular electrostatic potentials(MEP) were performed at the B3LYP/6-31G(d,p) level of theory. X-ray study shows that the title compounds both have strong intramolecular O-H…N hydrogen bonds. The molecules of Ⅰ are linked into a one-dimensional framework structure by C-H…π interactions,while in Ⅱ,intermolecular π···π interactions result in the formation of infinite chains running along the [010].     

游戏的规则公平吗？

<正>通过对这两年全国各地近300份中考数学试题的研究,我们发现,有不少试卷里设计了运用概率模型解释、判断游戏是否公平的问题.略举几例.例1(2013年杭州)某班有50位学生,每位学生都有一个序号,将50张编有学生序号(从1号到50号)的卡片(除序号不同外其它均相同)打乱顺序重新排列,从中任意抽獉獉獉取獉1獉张獉卡片.(1)在序号中,是20的倍数的有:20,40,能整除20的有:1,2,4,5,10(为了不重复计数,20只计一次),求取到的卡片上序号是20的倍数或能整除20的概率;(2)若规定:取到的卡片上序号是k(k是满足1≤k≤50的整数),则序号是k的倍数或     

Synthesis,Crystal Structure and Na~+/K~+-ATPase Inhibitory Activity of △~(14,15)-anhydro-24-thiocarbonylbufalin

The title compound △14,15-anhydro-24-thiocarbonylbufalin(1) was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H30O2S·C24H30O2S, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2, with a = 30.9845(2), b = 6.8036(3), c = 22.5791(15) , V = 4241.7(4) 3, Mr = 384.21, Z = 4, Dc = 1.204 g/cm3, μ = 1.463 mm-1, F(000) = 1664, S = 1.064, R = 0.0487 and wR = 0.0645 for 4683 unique reflections, of which 3757 were observed(I 2■(I)). The asymmetric unit contains two independent molecules(I and Ⅱ), which are closely similar to each other except for the orientation of the lactone ring. Both conformations of I and Ⅱ are in good agreement with the solution structure in methanol as indicated by 1H-NMR analysis. Due to the presence of heavy atom sulfur in the molecules, the final refinement resulted in a small Flack parameter 0.02(3), permitting the assignments of the absolute configuration. In the solid state, intermolecular hydrogen bonds involving thiocarbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed weak inhibition on Na+/K+-ATPase in contrast to the strong inhibitory activity of the parent compound bufalin, suggesting that the carbonyl group in lactone moiety and the hydroxyl group at C-14 play important roles for the inhibition of Na+/K+-ATPase.     

Synthesis and Characterization of a Manganese(Ⅱ) Coordination Compound with Two-dimensional Layer Structure: {[Mn_2(IP)_2(1,4-bdc)_2]·H_2O}n

A new complex {[Mn2(IP)2(1,4-bdc)2]·H2O}n(1)(IP = 1H-imidazo[4,5-f][1,10]-phenanthroline, 1,4-H2 bdc = 1,4-benzendicarboxylic acid), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group Cc with a = 20.326(2), b = 24.249(2), c = 7.621(1), β = 108.546(6), V = 3561.2(7)3, Z = 4, Dc = 1.672 g/cm3, μ = 0.785 mm-1, F(000) = 1824, S = 1.067, the final R = 0.0299 and wR = 0.0752. Compound 1 possesses a 2D structural motif, in which two crystallographically independent 1,4-bdc dianions adopt the alternative mode of mixed bis(bidentate) and monodentate-bidentate coordination modes to bridge neighboring Mn(II) centers. And the 2D layers are linked up by hydrogen bonding and π···π stacking interactions to form a 3D network. The title compound has good thermal stability and exhibits photoluminescent emission maximum at 518 nm.     

Hydrothermal Synthesis,Structural Investigation and Characterization of an Organic-inorganic Hybrid, [Co（BIIM）3]2H[BW12040]·7H2O

An organic-inorganic hybrid based on a-Keggin-typed [BWI2040]5- anionic cluster, [Co（BIIM）3]2H[BWx2040]＇7H20 （BIIM = 2,2＂-biimidazole）, was hydrothermally synthesized and structurally characterized by thermogravimetric analysis, IR and UV spectra. The title compound crystallizes in monoclinic, space group P21/n with a = 12.3490（10）, b = 33.270（3）, c = 18.9660（16） A, β = 105.9950（10）°, V= 7490.5（11） A3, C36HsoBCo2N24047W12, Mr = 3905.80, Dc = 3.45 l g/cm3, μ（MoKa） = 18.886 rnm-1, F（000） = 6972, Z = 4, S = 1.004, the final R = 0.0404 and wR = 0.0914 for 14683 observed reflections （1 〉 2tr（/））. The compound consists of two isolated [Co（BIIM）3]2＋ cations and one [BW12040]5 anion, in which each Co2＋ ion is coordinated by six N atoms from three BIIM ligands displaying a regular CoN6 octahedron. These components are finally linked together via N-H...O（polyoxometalate and wate） hydrogen bonds into a two-dimensional framework. Full investigation of the intermolecular interactions by Hirshfeld surface and fingerprint plots clearly indicates that there are rare W--Oterminal···πimidazole ring interactions which cooperate with the classical N-H···O hydrogen bonds to stabilize the structural packing.     

Urothermal Synthesis,Crystal Structure,and Luminescent Property of a New Zn（II） Coordination Polymer Constructed from Terephalic Acid and 5-Methyl-1H-tetrazole Ligands

A new luminescent Zn（II） compound, [Zn（pbdc）0.5（mtz）（DMPU）]n （1,H2pbdc = terephthalic acid, Hmtz = 5-methyl-1H-tetrazole, DMPU = N,N＇-dimethylpropyleneurea）, has been urothermally synthesized and characterized by elemental analysis, IR, X-ray powder diffraction （PXRD） and single-crystal X-ray diffraction. The title compound crystallizes in orthorhombic Pbca space group with α = 17.2649（5）, b = 10.4680（3）, c = 17.4457（7） ？, V = 3152.94（18） ？3, C12H17N6O3Zn, Mr = 358.71, Z = 8, Dc = 1.511 g/cm3, F（000） = 1480, μ = 1.579 mm-1, the final R = 0.0379 and wR = 0.0971 for 2785 observed reflections （I 〉 2σ（I））. Single-crystal X-ray structural analysis reveals that compound 1 features a 2D undulated layer with a 3-connected hcb topology. Moreover, the luminescent properties of 1 have also been investigated in the solid-state at room temperature.     

Synthesis,Crystal Structure and Biological Activity of Diethyl 1,4-dihydro-2,6-dimethyl-4-（4-methyl-1,2,3-thiadi azol-5-yl） pyridine-3,5-dicarboxylate

The title compound diethyl 1,4-dihydro-2,6-dimethyl-4-(4-methyl-1,2,3-thiadiazol-5-yl) pyridine-3,5-dicarboxylate(C16H21N3O4S, Mr = 351.42) was prepared by the Hantszch reaction with 4-methyl-1,2,3-thiadiazole-5-formaldehyde, ethyl acetoacetate and ammonium acetate in the presence of aluminum chloride in alcohol, and its structure was characterized by IR spectra, 1H-NMR, EA, and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic system, space group P21/n with a = 11.300(2), b = 12.771(3), c = 12.826(3) ?, β = 96.55(3)o, V = 1839.0(6) ?3, Z = 4, Dc = 1.296 g/cm3, μ(MoKa) = 0.71073 mm-1, F(000) = 744, R = 0.0981 and wR = 0.1994. X-ray diffraction result shows that the torsion angles of N(1)–C(2)– C(3)–C(4) and C(2)–C(3)–C(4)–C(8) are 178.9(3)° and –130.3(3)°, respectively. All rings in the title compound are non-planar. The bioassay results indicate that the title compound has good fungicidal activity, good antivirus activity against tobacco mosaic virus and certain extent of insecticidal activity against Mythimna separata.     

（2D ＋ 1D） Hydrogen Bond Structure Constructed. from Dendrimer Precursor

The title compound, CsH12NO4＂2（H20） 1, was obtained by slow diffusion of cop- per sulfate solution into the solution of 1,4-N,N-bis[tri（hydroxy）methyl]terephthaldiamide in DMSO and characterized by elemental analysis and infrared spectra. The crystal of 1 crystallizes in the monoclinic space group P2Jc with a = 12.943（7）, b = 6.446（3）, c = 14.157（5） A, fl = 119.76（3）, V = 1025.4（9）/3, Z = 2, C16H32N2OI2, Mr= 444.44, Dc= 1.439 g/cm3, F（000） = 476 and/（MoKa） = 0.123 mm＂1. The final R = 0.0484 and wR = 0.1080 for 1776 observed reflections with 1〉 2r（/） and R = 0.0679 and wR = 0.1183 for all data. X-ray diffraction reveals that the （2D＋ID） hydrogen bonds pillar the structure into an open 3D supramolecular framework with a pore along the b axis （approximate dimensions 5.9＊10.5 /2）, which is occupied by free water molecules. Photolu- minescent investigation reveals that the title compound displays an emission in the blue region.     

Synthesis,and Experimental and Theoretical Characterization of 3-（4-（Dimethylamino） benzylidene）-l,5-dioxaspiro [5.5] Undecane-2,4-dione

The title molecule, 3-（4-（dimethylamino）benzylidene）-l,5-dioxaspiro[5.5] unde- cane-2,4-dione （I）, was synthesized and characterized by elemental analysis, IR, UV-vis spectra and X-ray diffraction analysis. The compound belongs to the triclinic system, space group Pi with a = 6.3640（6）, b = 7.7404（8）, c = 16.2890（18） A, α = 86.860（2）, β = 85.837（2）, γ = 79.6720（10）°, V = 786.60（14） A3, D, = 1.331 g/cm3, and F（000） = 336. Geometrical structure of the title compound was optimized by density functional theory （DFT） using B3LYP method with 6-31G＊＊ as the basis set. The vibrational frequencies were calculated by the DFT method and the results are consistent with the observed frequencies. The electronic absorption spectra were studied with the time- dependent density functional theory （TD-DFT）, showing the calculation results in good agreement with the corresponding experimental data.     

Facile Synthesis and Crystal Structures of New Ammonium Sulfonates （CA-DNBS and TEA-TMBS）

The title compounds, C12HIoN307SCI （I） and C15H27NO3S （II）, crystallize in the monoclinic system, space group P21/c with a = 7.3995（1）, b = 27.8489（6）, c = 9.8246（2）/, fl = 131.349（1）, V = 1519.82（5） A3, Z = 4, F（000） = 768, Rint = 0.033 and S = 1.03 for I, and in the orthorhombic system, space group Pbca with a = 8.6227（1）, b = 16.1480（4）, c = 23.8774（6）/, V= 3324.67（12） A3, Z = 8, F（000） = 1312, Rint = 0.024 and S = 1.04 for II. We have devised a convenient procedure for the synthesis of fused organic salts resulting from 1：1 proton-transfer, using an amine and a derivative ofbenzenesulfonic acid. The synthesized salts have a number of applications ranging from their consumption as eco-friendly solvents and catalysts in organic syntheses, to being used as efficient precursors for the production of sulfa drugs. Structures of compounds 3-chloroanilinium 2,4-dinitrobenzenesulfonate （CA-DNBS） and triethylaminium 2,4,6-trimethylbenzenesulfonate （TEA-TMBS） were determined by single-crystal X-ray diffraction studies and infrared spectroscopy.