Synthesis and Crystal Structure of Ethyl 4-（2-Chloro-4-fluorophenyl）-6-hydroxy-3-oxo-1,3-dihydro-5-isobenzofurancarboxylate

The crystal structure of the title compound(C17H12ClFO5,Mr=350.72) was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/c,with a=7.693(1),b=15.767(1),c=12.986(1),β=97.23(1)°,V=1562.6(2)3,Z=4,Dc= 1.491 g/cm3,λ(MoKα)=0.71073,F(000)=720,μ(MoKα)=0.280 mm-1,R=0.0563 and wR=0.1674.A total of 3592 unique reflections were collected,of which 2462 with Ⅰ2σ(Ⅰ) were observed.Five-membered lactone rings and hydroxyl-substituted phenyl rings are approximately coplanar with their dihedral angle of 4.1°.The dihedral angle between two different phenyl rings is 71.3°.To our interest,intramolecular O(1)-H(1)···O(4) hydrogen bonds could be found in each molecule.Intramolecular hydrogen bonds and intermolecular van der Waals force contribute to the stability of the structure.     

（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].     

Synthesis and Crystal Structure of Bis（2-acetylpyridine thiosemicarbazonato）-indium（iii） Perchlorate Hydrate

The title complex bis(2-acetylpyridine thiosemicarbazonato)-indium(iii) perchlo-rate hydrate has been synthesized by the reaction of 2-acetylpyridine thiosemicarbazide(L) with indium(iii) perchlorate,and its structure was characterized by elemental analysis,IR and single-crystal X-ray diffraction.The crystal of the title compound([In(C8H9N4S)2]ClO4·H2O) belongs to monoclinic,space group P21/c with a = 12.6438(18),b = 12.6259(18),c = 15.116(2) nm,β = 105.800(2)°,Z = 4,V = 2321.9(6) nm3,Mr = 618.79,Dc = 1.770 g/cm3,μ = 1.359 mm-1,F(000) = 1240,R = 0.0265 and wR = 0.0675.X-ray analysis indicates that various intriguing hydrogen patterns involving both the solvent intermedia and polyatomic counterions play crucial roles in the self-assembly of functional supramolecules.     

Crystal and Molecular Structure of Ethyl 2-[（4-Hydroxy-phenyl）hydrazono]-3-oxobutanoate

The title compound,C 12 N 2 O 4 H 14 (M r=250.3),crystallizes in triclinic P1 space group with a=7.7709(9),b=8.7534(11),c=9.6958(12),α=77.103(2),β=80.496(2),γ=86.726(2)o,V=633.9(1) 3,Z=2,F(000)=264,D c=1.311 Mg/m 3,μ(MoKα)=0.1 mm-1,the final R=0.056,and wR=0.15 for 2239 observed reflections (I > 2σ(Ⅰ)).The molecules in the crystal are linked through O-H···O type of hydrogen bonding interaction forming an infinite chainlike structure.The phenylhydrazone ring and oxobutanoate groups are almost planar.The keto hydrazo group adopts a Z-configuration in the molecule and the torsion angle is-177.6(2)°.     

Facile Synthesis and Crystal Structure of a Novel Cyanopyridine

The title compound 2-amino-4-(4-hydroxy-3,5-dimethoxyphenyl)-5-methyl-6-phenyl nicotinonitrile,C 21 H 19 N 3 O 3,was synthesized via four-component reactions between propio-phenone,malononitrile,syringaldehyde and ammonium acetate in ethanol under reflux without catalyst and characterized by IR,1 H NMR,13 C NMR,MS,EA and single-crystal X-ray diffraction.Single-crystal X-ray diffraction analysis shows that the compound is of monoclinic system,space group P2 1 /n with a=8.4600(17),b=17.139(3),c=13.408(3),β=107.06(3)°,V=1858.6(6)3,Z=4,M r=361.39,F(000)=760,μ(MoKα)=0.088 mm-1,D c=1.292 g/cm 3,λ=0.71073,the final R=0.0751 and wR=0.0938 for 3333 observed reflections with I > 2σ(I).The crystal packing of the title compound is stabilized by intermolecular hydrogen bonds.     

Structure and Luminescence Property of a Hexanuclear Silver（Ⅰ） Cluster Containing Benzaldehyde Thiosemicarbazone

A new hexanuclear silver (I) compound 2 containing thiosemicarbazone with the group of benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound crystallizes in triclinic, space group P with a = 11.611(3), b = 15.610(5), c = 15.624(7) , α = 113.942(6), β = 104.520(6), γ = 104.230(4)°, V = 2304.1(14) 3, C60H77Ag6N22O4.5S6, Mr = 2018.02, Dc = 1.454 g/cm3, μ(MoKα) = 1.435 mm-1, F(000) = 1005, Z = 1, the final R = 0.0468 and wR = 0.1474 for 6608 observed reflections (I > 2σ(I)). In the structure, the S atom of the ligand L2 (L2 = benzaldehyde thiosemicarbazone) served as a triply bridged chelator to connect the six silver atoms into a Ag6L26 cluster. The luminescence property of compound 2 was investigated at room temperature.     

Hydrothermal Synthesis and Crystal Structure of a Novel Polymolybdate with Two Kinds of Organonitrogen Ligands

A novel inorganic-organic compound (C4N2H12)(C2N2H10)2[Mo5P2O23] (1) has been synthesized by the reaction of (NH4)2MoO4, H3PO4, C2N2H8 (ethylenediaminium), C4N2H10·6H2O (piperazine hexahydrate) and water in aqueous solution under mild hydrothermal conditions. Single-crystal X-ray analysis reveals that the title compound is crystallized in the triclinic system, space group P1 with a = 9.258(19), b = 9.382(19), c = 17.681(4), α = 76.28(3), β = 84.48(3), γ = 70.82(3)o, V = 1408.9(6)3, Mr = 1122.04, Z = 2, Dc = 2.645 g/cm3, μ = 2.384 mm-1, F(000) = 1092.0, the final R = 0.0391, wR = 0.1185 and S = 1.006 for 6169 observed reflections with I > 2σ(I). The crystal packing is stabilized by intra- and intermolecular N-H···O hydrogen bonds to form an infinite 3D network.     

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.