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911.
912.
Chun‐Xiang Wang Zhi‐Feng Li Ping Wang 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):m473-m475
In the title compound, [Nd2(C4H4O4)2(C2O4)(H2O)2]n, the flexible succinate anion assumes the gauche conformation and bridges the nine‐coordinate Nd atoms to generate two‐dimensional layers parallel to (010). The coordination polymer layers are linked into a three‐dimensional framework by the rigid oxalate ligands. The oxalate ions are located on a center of inversion. 相似文献
913.
A multireference configurational interaction method based on the separated electron pair (SEP) wave functions, SEP‐CI approach, has been developed as an approximation to the traditional CASSCF method. It differs from the CASSCF method in that active orbitals are obtained from the SEP wave function without further optimization in the subsequent CI calculations, and the active space is automatically constructed according to the occupation coefficients of SEP natural orbitals. These features make the present SEP‐CI method computationally much less demanding than the CASSCF method. The applicability of the SEP‐CI method is illustrated with sample calculations on the insertion reaction of BeH2 and dissociation energies of LiH, BH, FH, H2O, and N2. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 39–47, 2006 相似文献
914.
Chun‐Xiang Wang Chen‐Xia Du Zhi‐Feng Li 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):m488-m490
In the title compound, [Zn(C17H10N5O)2(H2O)2]·4H2O, cyclic water hexamers forming one‐dimensional metal–water chains are observed. The water clusters are trapped by the co‐operative association of coordination interactions and hydrogen bonds. The ZnII ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two O atoms and two N atoms from two 2′‐(4,5‐diazafluoren‐9‐ylidene)picolinohydrazidate ligands and two water molecules. 相似文献
915.
Cu(I)/Diamine-catalyzed Aryl-alkyne Coupling Reactions 总被引:1,自引:0,他引:1
Ye Feng WANG Wei DENG Lei LIU Qing Xiang GUO 《中国化学快报》2005,16(9):1197-1200
Arylalkynes are important building blocks for the synthesis of natural products,pharmaceuticals,and artificial molecular devices1.They are often synthesized via the Pd-catalyzed Sonogashira coupling reactions between aryl halides and terminal alkynes2,3.Unfortunately,it remains difficult to apply the Sonogashira reaction to industrial scale and/or pharmaceutical synthesis,due to the high cost of Pd and the difficulty in removing the toxic Pd residues from the reaction products.Thus it is wor… 相似文献
916.
A solution-phase synthesis of bicyclic prolines containing four points of diversity has been developed by a two-step synthesis involving 1,3-dipolar cycloaddition of perfluoroalkylsulfonyl-protected hydroxybenzaldehydes followed by Pd-catalyzed Suzuki coupling reaction of fluorous sulfonates with boronic acids. Both reactions are conducted under microwave irradiation and reaction mixtures are purified by solid-phase extractions without performing chromatography. 相似文献
917.
Lead diethyldithiocarbamate is an effective reagent for preconcentration of mercury in urine for neutron activation analysis. Sodium and bromine are removed from the sample by this procedure. As lead diethyldithiocarbamate is insensitive to neutron activation, radiochemical separation is not needed after neutron irradiation. Results from the analysis of urine collected from workers in caustic soda manufacturing plants are discussed. 相似文献
918.
Shu Jiang ZHANG Yan Feng LI Xiao Long WANG Da Xue YIN Yu SHAO Xin ZHAO 《中国化学快报》2005,16(9):1165-1168
A new aromatic diamine monomer containing pyridine unit, 2,6-bis (4-aminophenoxy- 4'-benzoyl)pyridine(BABP), was synthesized in three steps, starting from 2,6-pyridinedicarboxyl chloride. A series of novel pyridine-containing polyimides were prepared v/a the polycondensation of BABP with various aromatic dianhydrides through poly(amic acid) precursors, and thermal or chemical imidization of the precursors. The polyimides exhibit desirable properties, e.g., good solubility in N-methyl-2-pyrrolidone and m-cresol, excellent thermal stability and film-forming capability, as well as high inherent viscosity, indicating high molecular weight. 相似文献
919.
在氧离子导体La2Mo1.7W0.3O9的基础上,采用固相法合成了La位掺杂的Ca系列新型氧化物La2-xCaxMo1.7W0.3O9-δ(0≤x≤0.2)。通过XRD、Raman和XPS等手段对化合物结构进行表征,交流阻抗谱测试其电性能。结果表明:掺杂离子Ca2+的半径小于基质离子La3+的半径导致晶格收缩;Ca的掺杂在La2Mo1.7W0.3O9自身内置氧空位的基础上增加了额外的氧空位,提高了氧离子导体的电导率,550 ℃电导率由0.79 × 10-4 S·cm-1 (x=0.0)增加到1.5 × 10-4 S·cm-1 (x=0.16,0.2),电导率增加89.9%。 相似文献
920.
Li Zhang Xin‐An Chang Xue‐An Chen He‐Gui Zang Wei‐Qiang Xiao 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):i76-i78
The title compound represents a new structure type, in which distorted VO6 octahedra are bridged by iodate groups to form infinite two‐dimensional [VO2(IO3)2]− layers that are separated by octahedrally coordinated Li+ cations. 相似文献