The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione, bartbituric acid and 2-thiobarbituric acid proceede...The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione, bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.展开更多
The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H1...The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H15N2O3)3(H2O)]DMFH2O. The coordi- nation sphere about each copper ion in the complex consists of two oxygen atoms from hydroxylpyridinone moiety of one ligand and one oxygen and one nitrogen atoms from salicyladehyde Schiff-base moiety of another ligand arranged in a slightly distorted square planar geometry. Among the three copper ions, one (Cu(2)) is coordinated by the other oxygen atom of water molecule on the fifth coordinate position to form a distorted square pyramid geometry. The crystal is of monoclinic, space group P21/c with a = 12.9202(5), b = 27.197(1), c = 17.0116(7) ? b = 100.588(1), V = 5875.9(4) 3, Z = 4, C63H57N7O12Cu3, Mr = 1294.78, Dc = 1.464 g/cm3, m = 1.146 mm-1, F(000) = 2668, R = 0.0784 and wR = 0.1546 for 6926 observed reflections with I > 2s(I). The differences of coordinate bond lengths are observed between anhydrous and hydrous units: in the former unit, the average bond lengths are 1.978 ?for CuN (azomethine), 1.883 ?for CuO (phenolic) in Schiff-base moiety, 1.959 ?for CuO (keto), and 1.919 ?for CuO (hydroxy) in hydroxypyridinone moiety; while those in the latter are longer with the following corresponding values: 1.985(5), 1.908(5), 1.993(5) and 1.919(4) ? respectively. The Cu(2)O (water) bond length is 2.375(6) ?展开更多
The title compound methyl (7,7-dimemyl-2-amino-4-(4-chlorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran-3-yl) carboxylate (C19H20ClNO4, Mr = 361.81) was synthesized and crystallized. The crystal belongs to tricl...The title compound methyl (7,7-dimemyl-2-amino-4-(4-chlorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran-3-yl) carboxylate (C19H20ClNO4, Mr = 361.81) was synthesized and crystallized. The crystal belongs to triclinic, space group P 1 with a = 8.519(2), b = 10.346(2), c = 11.481(3) A, α = 108.16(1), β = 107.78(2), γ= 91.83(2)°, Z = 2, V = 906.5(3) A3, Dc = 1.326 g/cm3, μ(MoKα) = 0.234 mm-1, F(000) = 380, R = 0.0467 and wR = 0.1270 for 3142 observed reflections (I > 2σ(I)). X-ray analysis reveals that the C(7), C(8), C(9), O(1), C(10) and C(11) atoms form a six-membered ring which adopts a boat conformation. In the ring, the distances of C(8)-C(9) and C(10)-C(11) are 1.332(3) and 1.357(3) A, respectively, which indicates that they are C=C double bonds. Another six-membered ring (C(8)-C(9)-C(15)-C(14)-C(13)-C(12)) adopts the half-chair confonnation. In addition, there are intermolecular hydrogen bonds in the crystal structure.展开更多
The title compound ethyl(2-amino-4-(3-nitrophenyl)-1,4-dihydro-2H-pyrano[3,2- h]quinolin-3-)carboxylate (C21H17N3O5, Mr = 391.38) was synthesized and crystallized. The crystal belongs to triclinic, space group P?with ...The title compound ethyl(2-amino-4-(3-nitrophenyl)-1,4-dihydro-2H-pyrano[3,2- h]quinolin-3-)carboxylate (C21H17N3O5, Mr = 391.38) was synthesized and crystallized. The crystal belongs to triclinic, space group P?with a = 7.886(1), b = 9.896(2), c = 12.575(3) ? a = 77.81(2), b = 82.69(2), g = 73.86(2), Z = 2, V = 919.0(3) ?, Dc = 1.414 g/cm3, m(MoKa) = 0.103 mm-1, F(000) = 408, R = 0.0421 and wR = 0.0973 for 2007 observed reflections (I > 2s(I)). X-ray analysis reveals that the C(6), C(7), C(10), C(11), C(12) and O(1) atoms form a six-membered ring which adopts a boat conformation. In the ring, the bond lengths of C(6)C(7) and C(10)C(11) are 1.360(2) and 1.361(2) ? respectively, indicating they are C=C double bonds.展开更多
Molecular programming is applied to minimum spanning problem whose solution requires encoding of real values in DNA strands. A new encoding scheme is proposed for real values that is biologically plausible and has a f...Molecular programming is applied to minimum spanning problem whose solution requires encoding of real values in DNA strands. A new encoding scheme is proposed for real values that is biologically plausible and has a fixed code length. According to the characteristics of the problem, a DNA algorithm solving the minimum spanning tree problem is given. The effectiveness of the proposed method is verified by simulation. The advantages and disadvantages of this algorithm are discussed.展开更多
The title compound 4-(3,4-methylenedioxylphenyl)-6-methyl-5-ethoxycaronyl-3,4- dihydropyrimidin-2(H)-one (C15H16N2O5) has been synthesized and determined by single-crystal X-ray diffraction. The crystal is of triclini...The title compound 4-(3,4-methylenedioxylphenyl)-6-methyl-5-ethoxycaronyl-3,4- dihydropyrimidin-2(H)-one (C15H16N2O5) has been synthesized and determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P with a = 7.580(1), b = 7.920(2), c = 13.168(4) ? a = 96.44(2), b = 96.71(2), g = 109.81(2), V = 728.8(3) 3, Z = 2, Mr = 304.30, Dc = 1.387 g/cm3, F(000) = 320, m(MoKa) = 0.105 mm-1 (l = 0.71073 ?, R = 0.0446 and wR = 0.1205. In the molecule the pyrimidine ring adopts a boat conformation.展开更多
We first establish a integral inequality for compact maximal space-like subman ifolds in pseudo-Riemannian manifolds Np(n+p). Then, we investigate compact space-like sub manifolds and hupersurfaces with parallel secon...We first establish a integral inequality for compact maximal space-like subman ifolds in pseudo-Riemannian manifolds Np(n+p). Then, we investigate compact space-like sub manifolds and hupersurfaces with parallel second fundamental form in Np(n+p) and some other ambient spaces. We obtain some distribution theorems for the square norm of the second fundamental form.展开更多
The title compound (C19H29NO4) has been synthesized by the reaction of pro- paldehyde with dimedone and hydroxylamine hydrochloride in glycol under microwave irradiation, and its structure was determined by single-c...The title compound (C19H29NO4) has been synthesized by the reaction of pro- paldehyde with dimedone and hydroxylamine hydrochloride in glycol under microwave irradiation, and its structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 12.533(1), b = 13.184(2), c = 11.883(2) ?, β = 109.06(1)°, V = 1856.0(5) ?3, Mr = 335.43, Z = 4, Dc = 1.201 g/cm3, λ = 0.71073 ?, μ(MoKα) = 0.083 mm-1 and F(000) = 728. The structure was refined to R = 0.0488 and wR = 0.1456 for 2306 observed reflections with I > 2σ(I). X-ray analysis reveals that the pyridine ring adopts a boat conformation, while two cyclohexanone rings have envelope conformations.展开更多
System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a ...System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a virtual mining system were discussed: optimizing 3D models to keep the polygon number in VR system within target hardware's processing ability; optimizing texture database to save texture memory with perfect visual effect; optimizing database hierarchy structure to accelerate model retrieval; and optimizing LOD hierarchy structure to speed up rendering.展开更多
The subsiding land can be extracted from Remote Sensing image based on itsspectral and spatial features. The features of subsiding land caused by raining, especially its RSinformation features and relative knowledge a...The subsiding land can be extracted from Remote Sensing image based on itsspectral and spatial features. The features of subsiding land caused by raining, especially its RSinformation features and relative knowledge are proposed. Three methods can be used to extractsubsiding land from RS image. The first is to categorize the region into different blocks (orlayers) according to their features and apply corresponding strategies for each block, the second isto identify the changeable region based on GIS firstly and then to classify those regions, and thethird is to post-process the classified image by traditional methods or ANN (Artificial NeuralNetwork) methods based on domain knowledge and GIS. Two direct extraction methods are introducedalso. One is the extraction based on the water accumulating property of subsiding land, and theother is based on the dynamic change of land cover in subsiding land.展开更多
The ratchet motion of a Brownian particle in a symmetric periodic potential under a rocking force thatbreaks the temporal symmetry is studied. As long as the relaxation time in the thermal background is much shorter t...The ratchet motion of a Brownian particle in a symmetric periodic potential under a rocking force thatbreaks the temporal symmetry is studied. As long as the relaxation time in the thermal background is much shorter thanthe forcing period, the unidirectional transport can be analytically treated. By solving the Fokker-Planck equations, weget an analytical expression of the current. This result indicates that with an appropriate match between the potentialfield, the asymmetric ac force and the thermal noise, a net current can be achieved. The current versus thermal noiseexhibits a stochastic-resonance-like behavior.展开更多
A range of rare earth metal complexes of 2-mercaptopyridine N-oxide (Hmpo) have been synthesized, and studied by elemental analysis and IR spectroscopic technique. Crystal structure of Dy(mpo)3(DMSO)2 (DMSO = dimethyl...A range of rare earth metal complexes of 2-mercaptopyridine N-oxide (Hmpo) have been synthesized, and studied by elemental analysis and IR spectroscopic technique. Crystal structure of Dy(mpo)3(DMSO)2 (DMSO = dimethyl sulfoxide) has been determined. The complex crystallizes in the triclinic system, space group P with lattice parameters: a = 9.602(3), b = 9.803(3), c = 15.498(5) ? a = 89.51(1), b = 85.73(1), g = 62.99(1)? Dc = 1.787 g/cm3, C19H24N3O5S5Dy, Mr = 697.21, Z = 2, F(000) = 690, = 3.321mm-1, the final R = 0.0237 and wR = 0.0587 for 4116 reflections with I > 2s(I). The coordination number of dysprosium (Ⅲ) is eight, and its coordination geometry is a somewhat distorted square antiprism with O(3), O(4), O(5), S(3) and O(1), O(2), S(1), S(2) at the tetragonal bases (dihedral angle between their mean planes is 2.9(1)). Around the Dy atom, three five-membered ring planes (Dy, O, N, C, S) make the dihedral angles of 74.42, 11.31 and 83.72, respectively.展开更多
The title compound (C22H27NO3) was obtained by the reaction of 4-methylbenzal- dehyde, dimedone, ethyl acetoacetate and ammonium acetate in water in the presence of triethyl- benzylammonium chloride (TEBA). The crysta...The title compound (C22H27NO3) was obtained by the reaction of 4-methylbenzal- dehyde, dimedone, ethyl acetoacetate and ammonium acetate in water in the presence of triethyl- benzylammonium chloride (TEBA). The crystal is of orthorhombic, space group Pbcn with a = 18.242(2), b = 15.651(1), c = 14.207(2) ?, V = 4056.15(64) ?3, Mr = 353.45, Z = 8, Dc = 1.158 g/cm3, μ = 0.076, λ(MoKα) = 0.71073 ? and F(000) = 1520. The final R = 0.0453 and wR = 0.0436 for 1156 observed reflections with I > 2σ(I). X-ray analysis revealed that the pyridine ring is of boat conformation and the six-member ring fused with it adopts half-chair conformation.展开更多
The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 18.520(2), b = 7.8910(1), c = 21.728(3) A, β = ...The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 18.520(2), b = 7.8910(1), c = 21.728(3) A, β = 104.77(1)°, V= 3070.4(7) A3, Mr= 303.31, Z = 8, Dc= 1.312 g/cm3, λ = 0.71073 A,μ(MoKα) = 0.098 mm-1 and F(000) = 1280. The structure was refined to R = 0.0486 and wR = 0.1287. There exist intermolecular hydrogen bonds in the crystal.展开更多
The crystal structure N-methyl-9-(4-bromophenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10- decahydroacridine(C20H20BrNO2) was determined by single-crystal X-ray diffraction analysis. It belongs to P21/n space group, with a = ...The crystal structure N-methyl-9-(4-bromophenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10- decahydroacridine(C20H20BrNO2) was determined by single-crystal X-ray diffraction analysis. It belongs to P21/n space group, with a = 10.7999(18), b = 13.845(3), c = 11.4031(3) ?, β = 99.324(4)°, Dc = 1.525 g/cm3, Z = 4, λ = 0.71070 ?, μ(MoKα) = 2.455 mm-1, Mr = 386.28, V = 1682.5(5) ?3, F(000) = 792, the final R = 0.0463 and wR = 0.1053. In the crystal structure, the pyridine ring adopts a boat conformation, the two six-numbered rings fused with pyridine ring adopt twisting boat con- formation.展开更多
The crystal structure of the title compound (C26H33NO4 (C25.68H32.04N0.68O4.32, Mr = 419.35)) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space P21/c with a = 7.519(2), b = ...The crystal structure of the title compound (C26H33NO4 (C25.68H32.04N0.68O4.32, Mr = 419.35)) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space P21/c with a = 7.519(2), b = 28.933(5), c = 10.654(3) ?, β = 91.78(2)°, V = 2316.7(7) ?3, Z = 4, Dc = 1.202 g/cm3, μ = 0.081 mm-1, F(000) = 902, Mr = 423, the final R = 0.0424 and wR = 0.0911. In the structure, the pyridine ring adopts a boat conformation.展开更多
文摘The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione, bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.
基金This work was supported by the foundation of Natural Science Research of Jiangsu Education Department (02KJB150007)
文摘The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H15N2O3)3(H2O)]DMFH2O. The coordi- nation sphere about each copper ion in the complex consists of two oxygen atoms from hydroxylpyridinone moiety of one ligand and one oxygen and one nitrogen atoms from salicyladehyde Schiff-base moiety of another ligand arranged in a slightly distorted square planar geometry. Among the three copper ions, one (Cu(2)) is coordinated by the other oxygen atom of water molecule on the fifth coordinate position to form a distorted square pyramid geometry. The crystal is of monoclinic, space group P21/c with a = 12.9202(5), b = 27.197(1), c = 17.0116(7) ? b = 100.588(1), V = 5875.9(4) 3, Z = 4, C63H57N7O12Cu3, Mr = 1294.78, Dc = 1.464 g/cm3, m = 1.146 mm-1, F(000) = 2668, R = 0.0784 and wR = 0.1546 for 6926 observed reflections with I > 2s(I). The differences of coordinate bond lengths are observed between anhydrous and hydrous units: in the former unit, the average bond lengths are 1.978 ?for CuN (azomethine), 1.883 ?for CuO (phenolic) in Schiff-base moiety, 1.959 ?for CuO (keto), and 1.919 ?for CuO (hydroxy) in hydroxypyridinone moiety; while those in the latter are longer with the following corresponding values: 1.985(5), 1.908(5), 1.993(5) and 1.919(4) ? respectively. The Cu(2)O (water) bond length is 2.375(6) ?
基金This work was supported by the foundation of the "Surpassing Project" of Jiangsu province
文摘The title compound methyl (7,7-dimemyl-2-amino-4-(4-chlorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran-3-yl) carboxylate (C19H20ClNO4, Mr = 361.81) was synthesized and crystallized. The crystal belongs to triclinic, space group P 1 with a = 8.519(2), b = 10.346(2), c = 11.481(3) A, α = 108.16(1), β = 107.78(2), γ= 91.83(2)°, Z = 2, V = 906.5(3) A3, Dc = 1.326 g/cm3, μ(MoKα) = 0.234 mm-1, F(000) = 380, R = 0.0467 and wR = 0.1270 for 3142 observed reflections (I > 2σ(I)). X-ray analysis reveals that the C(7), C(8), C(9), O(1), C(10) and C(11) atoms form a six-membered ring which adopts a boat conformation. In the ring, the distances of C(8)-C(9) and C(10)-C(11) are 1.332(3) and 1.357(3) A, respectively, which indicates that they are C=C double bonds. Another six-membered ring (C(8)-C(9)-C(15)-C(14)-C(13)-C(12)) adopts the half-chair confonnation. In addition, there are intermolecular hydrogen bonds in the crystal structure.
基金This work was supported by the Foundation of "urpassing Project"of Jiangsu province
文摘The title compound ethyl(2-amino-4-(3-nitrophenyl)-1,4-dihydro-2H-pyrano[3,2- h]quinolin-3-)carboxylate (C21H17N3O5, Mr = 391.38) was synthesized and crystallized. The crystal belongs to triclinic, space group P?with a = 7.886(1), b = 9.896(2), c = 12.575(3) ? a = 77.81(2), b = 82.69(2), g = 73.86(2), Z = 2, V = 919.0(3) ?, Dc = 1.414 g/cm3, m(MoKa) = 0.103 mm-1, F(000) = 408, R = 0.0421 and wR = 0.0973 for 2007 observed reflections (I > 2s(I)). X-ray analysis reveals that the C(6), C(7), C(10), C(11), C(12) and O(1) atoms form a six-membered ring which adopts a boat conformation. In the ring, the bond lengths of C(6)C(7) and C(10)C(11) are 1.360(2) and 1.361(2) ? respectively, indicating they are C=C double bonds.
文摘Molecular programming is applied to minimum spanning problem whose solution requires encoding of real values in DNA strands. A new encoding scheme is proposed for real values that is biologically plausible and has a fixed code length. According to the characteristics of the problem, a DNA algorithm solving the minimum spanning tree problem is given. The effectiveness of the proposed method is verified by simulation. The advantages and disadvantages of this algorithm are discussed.
基金Supported by the National Natural Science Foundation of China (No. 20372057) Natural Science Foundation of Jiangsu Province (No. BK2001142) and the Natural Science Foundation of Jiangsu Education Department (No. 01KJB150008) and Jiangsu Provincial
文摘The title compound 4-(3,4-methylenedioxylphenyl)-6-methyl-5-ethoxycaronyl-3,4- dihydropyrimidin-2(H)-one (C15H16N2O5) has been synthesized and determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P with a = 7.580(1), b = 7.920(2), c = 13.168(4) ? a = 96.44(2), b = 96.71(2), g = 109.81(2), V = 728.8(3) 3, Z = 2, Mr = 304.30, Dc = 1.387 g/cm3, F(000) = 320, m(MoKa) = 0.105 mm-1 (l = 0.71073 ?, R = 0.0446 and wR = 0.1205. In the molecule the pyrimidine ring adopts a boat conformation.
文摘We first establish a integral inequality for compact maximal space-like subman ifolds in pseudo-Riemannian manifolds Np(n+p). Then, we investigate compact space-like sub manifolds and hupersurfaces with parallel second fundamental form in Np(n+p) and some other ambient spaces. We obtain some distribution theorems for the square norm of the second fundamental form.
基金This work was supported by the National Natural Science Foundation of China (No. 20372057) the Open Foundation of Key Laboratory of Organic Synthesis of Jiangsu Province+1 种基金 College of Chemistry and Chemical Engineering Suzhou University (No. S8109111) and Key Lab of Biotechnology for Medicinal Plants of Jiangsu Province (No. 01AXL 14)
文摘The title compound (C19H29NO4) has been synthesized by the reaction of pro- paldehyde with dimedone and hydroxylamine hydrochloride in glycol under microwave irradiation, and its structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 12.533(1), b = 13.184(2), c = 11.883(2) ?, β = 109.06(1)°, V = 1856.0(5) ?3, Mr = 335.43, Z = 4, Dc = 1.201 g/cm3, λ = 0.71073 ?, μ(MoKα) = 0.083 mm-1 and F(000) = 728. The structure was refined to R = 0.0488 and wR = 0.1456 for 2306 observed reflections with I > 2σ(I). X-ray analysis reveals that the pyridine ring adopts a boat conformation, while two cyclohexanone rings have envelope conformations.
文摘System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a virtual mining system were discussed: optimizing 3D models to keep the polygon number in VR system within target hardware's processing ability; optimizing texture database to save texture memory with perfect visual effect; optimizing database hierarchy structure to accelerate model retrieval; and optimizing LOD hierarchy structure to speed up rendering.
基金Under the auspices of the Research Foundation of Doctoral Point of China(No.RFDP20010290006).
文摘The subsiding land can be extracted from Remote Sensing image based on itsspectral and spatial features. The features of subsiding land caused by raining, especially its RSinformation features and relative knowledge are proposed. Three methods can be used to extractsubsiding land from RS image. The first is to categorize the region into different blocks (orlayers) according to their features and apply corresponding strategies for each block, the second isto identify the changeable region based on GIS firstly and then to classify those regions, and thethird is to post-process the classified image by traditional methods or ANN (Artificial NeuralNetwork) methods based on domain knowledge and GIS. Two direct extraction methods are introducedalso. One is the extraction based on the water accumulating property of subsiding land, and theother is based on the dynamic change of land cover in subsiding land.
文摘The ratchet motion of a Brownian particle in a symmetric periodic potential under a rocking force thatbreaks the temporal symmetry is studied. As long as the relaxation time in the thermal background is much shorter thanthe forcing period, the unidirectional transport can be analytically treated. By solving the Fokker-Planck equations, weget an analytical expression of the current. This result indicates that with an appropriate match between the potentialfield, the asymmetric ac force and the thermal noise, a net current can be achieved. The current versus thermal noiseexhibits a stochastic-resonance-like behavior.
基金This work was supported by Xuzhou Normal University (00AXL003)
文摘A range of rare earth metal complexes of 2-mercaptopyridine N-oxide (Hmpo) have been synthesized, and studied by elemental analysis and IR spectroscopic technique. Crystal structure of Dy(mpo)3(DMSO)2 (DMSO = dimethyl sulfoxide) has been determined. The complex crystallizes in the triclinic system, space group P with lattice parameters: a = 9.602(3), b = 9.803(3), c = 15.498(5) ? a = 89.51(1), b = 85.73(1), g = 62.99(1)? Dc = 1.787 g/cm3, C19H24N3O5S5Dy, Mr = 697.21, Z = 2, F(000) = 690, = 3.321mm-1, the final R = 0.0237 and wR = 0.0587 for 4116 reflections with I > 2s(I). The coordination number of dysprosium (Ⅲ) is eight, and its coordination geometry is a somewhat distorted square antiprism with O(3), O(4), O(5), S(3) and O(1), O(2), S(1), S(2) at the tetragonal bases (dihedral angle between their mean planes is 2.9(1)). Around the Dy atom, three five-membered ring planes (Dy, O, N, C, S) make the dihedral angles of 74.42, 11.31 and 83.72, respectively.
基金This work was supported by the foundation of "Innovation Project" of Xuzhou Normal University
文摘The title compound (C22H27NO3) was obtained by the reaction of 4-methylbenzal- dehyde, dimedone, ethyl acetoacetate and ammonium acetate in water in the presence of triethyl- benzylammonium chloride (TEBA). The crystal is of orthorhombic, space group Pbcn with a = 18.242(2), b = 15.651(1), c = 14.207(2) ?, V = 4056.15(64) ?3, Mr = 353.45, Z = 8, Dc = 1.158 g/cm3, μ = 0.076, λ(MoKα) = 0.71073 ? and F(000) = 1520. The final R = 0.0453 and wR = 0.0436 for 1156 observed reflections with I > 2σ(I). X-ray analysis revealed that the pyridine ring is of boat conformation and the six-member ring fused with it adopts half-chair conformation.
基金Supported by the Natural Science Foundation of Jiangsu province(No.BK2001142)the Natural Science Foundation of Jiangsu Education Department(No.01KJB150008)
文摘The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 18.520(2), b = 7.8910(1), c = 21.728(3) A, β = 104.77(1)°, V= 3070.4(7) A3, Mr= 303.31, Z = 8, Dc= 1.312 g/cm3, λ = 0.71073 A,μ(MoKα) = 0.098 mm-1 and F(000) = 1280. The structure was refined to R = 0.0486 and wR = 0.1287. There exist intermolecular hydrogen bonds in the crystal.
基金This work was supported by the National Natural Science Foundation of China (No. 20372057) Natural Science Foundation of Jiangsu Province (No. BK2001142) the Suzhou University Organic Synthesis Open Laboratory of Jiangsu Province (No. S81091 11) and the Key Lab of Biotechnology for Medicinal Plants of Jiangsu Province (No. 01AXL 14)
文摘The crystal structure N-methyl-9-(4-bromophenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10- decahydroacridine(C20H20BrNO2) was determined by single-crystal X-ray diffraction analysis. It belongs to P21/n space group, with a = 10.7999(18), b = 13.845(3), c = 11.4031(3) ?, β = 99.324(4)°, Dc = 1.525 g/cm3, Z = 4, λ = 0.71070 ?, μ(MoKα) = 2.455 mm-1, Mr = 386.28, V = 1682.5(5) ?3, F(000) = 792, the final R = 0.0463 and wR = 0.1053. In the crystal structure, the pyridine ring adopts a boat conformation, the two six-numbered rings fused with pyridine ring adopt twisting boat con- formation.
基金The project was supported by the National Natural Science Foundation of China (No. 20372057) Natural Science Foundation+4 种基金 of Jiangsu Province (No. BK.2001142) the Open-end Fund of the Key Experiments of Organic Synthesis Jiangsu Province (S8109111) the Fund of Jiangsu Provincial Key Lab of Biotechnology for Medicinal Plants (01AXL 14)
文摘The crystal structure of the title compound (C26H33NO4 (C25.68H32.04N0.68O4.32, Mr = 419.35)) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space P21/c with a = 7.519(2), b = 28.933(5), c = 10.654(3) ?, β = 91.78(2)°, V = 2316.7(7) ?3, Z = 4, Dc = 1.202 g/cm3, μ = 0.081 mm-1, F(000) = 902, Mr = 423, the final R = 0.0424 and wR = 0.0911. In the structure, the pyridine ring adopts a boat conformation.
