Se和Se@C纳米棒的选择合成

通过调节葡萄糖浓度,采用十六烷基三甲基溴化铵(CTAB)辅助水热法选择合成了Se和Se@C纳米棒,并用扫描电镜(SEM)、透射电镜(TEM)、粉末X射线衍射(XRD)和X射线能谱分析(EDS)对产物进行了表征。结果表明,产物Se纳米棒直径200～300 nm,长达数微米;Se@C纳米棒长达数微米,内核直径200～00 nm,壳厚约30 nm。初步探讨了Se和Se@C纳米棒的生长机制。     

三维分级结构氢氧化钴的合成

以硝酸钴为钴源,采用十六烷基三甲基溴化铵(CTAB)辅助,通过水热法合成了具有三维分级结构的β-Co(OH)2微球.采用粉末X射线衍射(XRD)、能谱元素分析(EDS)和扫描电镜(SEM)对产物进行表征.实验结果表明,产物β-Co(OH)2为由直径1～2μm和厚度约500nm的纳米板组装而成的微球.考察了CTAB的浓度、pH值和温度对产物形貌的影响.结果表明,CTAB的浓度和pH值对最终产物的形貌具有重要影响,而当水热温度在140～180℃区间内,反应温度对产物的形貌无影响.通过监控不同反应时间所获产物的形貌,初步探讨了三维结构的β-Co(OH)2的生长机制.     

具有主导晶面的BiOIO3/BiOCl异质结制备与光催化性能

分别以乙二醇/去离子水为溶剂,通过溶剂热/水热法分别制备了具有不同主导晶面的BiOIO₃/{110}BiOCl和BiOIO₃/{001}BiOCl异质结。采用X射线衍射、扫描电子显微镜、能量色散谱和紫外可见漫反射光谱对制备的BiOIO₃/BiOCl光催化剂进行了表征。在可见光照射下,通过对罗丹明B和苯酚水溶液的光催化降解,考察了BiOIO₃/BiOCl异质结的光催化活性。结果显示25%BiOIO₃/{110}BiOCl异质结具有最高的光催化效率。BiOIO₃/{110}BiOCl较好的光催化性能是由于其在可见光区较强的光吸收,以及异质结结构和BiOCl所具有的(110)主导晶面有利于光生载流子的分离。超氧自由基(·O₂^-)和空穴(h⁺)是光催化过程中的主要活性物质。此外,根据实验结果探讨了光催化性能增强的机理。     

The First Principle Study on the Rectification of Molecular Junctions Based on the Alkyl-chain-modified Phenyl Benzothiophene Derivative

Using density functional theory(DFT) combined with nonequilibrium Green's function investigates the electron-transport properties of several molecular junctions based on the PBTDT-CH=NH molecule, which is modified by one to four alkyl groups forming PBTDT-(CH_2)_nCH=NH. The electronic structures of the isolated molecules(thiol-ended PBTDT-(CH2)_nCH=N) have been investigated before the electron-transport calculations are performed. The asymmetric current-voltage characteristics have been obtained for the molecular junctions. Rectifying performance of Au/S-PBTDT-CH=N-S/Au molecular junction can be regulated by introducing alkyl chain. The N3 molecular junction exhibits the best rectifying effect. Its maximum rectifying ratio is 878, which is 80 times more than that of the molecular junction based on the original N molecular junction. The current-voltage(I-V) curves of all the sandwich systems in this work are illustrated by transmission spectra and molecular projection density analysis.     

Unprecedented Pseudo Water Tapes Stabilized by a One-dimensional Cu（Ⅱ） Coordination Polymer

A new compound,[Cu(mal)(tmdpy)(H2O)]·4H2O(1,H2mal = malonic acid,tmdpy = 4,4'-trimethylenedipyridine) has been synthesized by the hydrothermal synthesis and structurally characterized by X-ray crystallography. It crystallizes in triclinic,space group P1 with a = 9.1662(6),b = 10.6266(7),c = 11.3056(7) ,α = 84.6390(10),β = 72.1030(10),γ = 73.0420(10) o,V = 1002.37(11) 3,C16H26CuN2O9,Mr = 453.93,Z = 2,Dc = 1.504 g/cm3,μ = 1.140 mm-1,F(000) = 474,R = 0.0375 and wR = 0.0975 for 3187 observed reflections(I > 2σ(I)) . In the structure of 1,the tmdpy ligands link the [Cu(mal)(H2O) ] units into an infinite chain,and the water molecules and carboxylate oxygen donors(O(2) and O(4)) from the mal ligands cooperatively built an interesting hydrogen bonding network with unprecedented pseudo water tape substructures.     

系列新型硫杂杯[4]芳烃氮杂衍生物的合成

在对叔丁基硫杂杯[4]芳烃的下缘1,3位引入芳醛基, 合成了硫杂杯[4]二醛基衍生物2. 化合物2与苯胺、水杨酰肼、烟酰肼、异烟酰肼等通过席夫碱缩合反应得到新型硫杂杯[4]氮杂衍生物3a～3d, 产率分别为83%, 80%, 77%和79%. 化合物2与邻苯二胺、乙二酰肼、丙二酰肼、己二酰肼等通过“1＋1”分子间缩合得到新型1,3-桥联硫杂杯[4]氮杂衍生物4a～4d, 产率53%, 51%, 59%和66%. 新化合物的结构经IR, ¹H NMR, MS和元素分析等证实.     

磷酸二甲酯阴离子(DMP~-)与一价、二价金属离子 相互作用的理论研究

在B3LYP、HF和MP2水平上运用全电子从头算(AE)和相对论有效实势(RECP)及6-311+G**和LanL2DZ基组计算Ⅰa、Ⅰb、Ⅱa和Ⅱb族金属离子与磷酸二甲酯阴离子(DMP-)的相互作用。 RECP用于除Li+、Be2+外所有的金属离子。 对Na+、K+、Cu+、Mg2+、Ca2+、Zn2+用AE和RECP 2种方法处理。 结果表明:RECP能可靠地用于重金属离子络合物; 二价金属离子络合物(DMP-—M2+)比一价金属离子络合物 (DMP-—M+)稳定;二价金属离子(M2+)可能比一价金属离子(M+)更易使多核苷酸折叠。     

Synthesis,Structure and Luminescent Property of a New Zn(Ⅱ) Coordination Polymer Based on 1,3,5-Benzenetricarboxylate and 4,4'-Bipyridine Ligands

A new Zn(II) coordination polymer [Zn3(BTC)2(4,4'-bpy)(CO)2]n(1, H3 BTC =1,3,5-benzenetricarboxylic acid, 4,4'-bpy = 4,4'-bipyridine) has been prepared through urothermal reaction of zinc nitrate hexahydrate with 1,3,5-benzenetricarboxylic acid and 4,4'-bipyridine, and characterized by elemental analysis, IR spectroscopy, TGA and powder XRD, and its crystal structure was determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in the monoclinic system, space group C2/c, with a = 10.262(3), b = 18.838(5), c =15.083(4) A, β = 99.203(4)o, V = 2878.3(14) A3, C30H14Zn3N2O14, Mr = 822.54, Z = 4, Dc = 1.898g/cm3, μ = 2.561 mm-1, F(000) = 1640, R = 0.0363 and w R = 0.0932 for 2828 observed reflections(I 2σ(I)). X-ray analysis shows that the asymmetric unit of the title compound contains two crystallographically unique Zn(II) atoms which are connected by BTC3- ligands and 4,4'-bpy coligands to form a 3D framework with 1D channels. The solid luminescence of ligand and the title complex was also studied at room temperature.     

α-MnO2和β-MnO2纳米棒的制备和催化性能研究

α-MnO₂ and β-MnO₂ nanorods were prepared directly by facile hydrothermal process at 150 ℃ and 220 ℃, respectively. The as-prepared α-MnO₂ and β-MnO₂ nanorods were shown to be phase-pure single crystallites as evidenced by XRD, TEM and SEM results. Further experiments show that the as-prepared α-MnO₂ and β-MnO₂ nanorods have catalytic effect on the oxidation and decomposition of the methylene blue(MB) dye with H₂O₂. The catalytic activity of β-MnO₂ is much higher than that of α-MnO₂.     

Synthesis and Crystal Structure of a New Zn(Ⅱ) Coordination Polymer Constructed by 1,2,4,5-Benzenetetracarboxylate

A new Zn(Ⅱ) coordination polymer [Zn3(btec)(OH)2(H2O)2]n (1, btec = 1,2,4,5- benzenetetracarboxylate) has been synthesized by hydrothermal reaction and its structure was determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in mono- clinic, space group C2/c, with a = 19.580(3), b = 5.0137(8), c = 15.975(3), β = 121.629(2)°, V = 1335.3(4)3, C10H8O12Zn3, Mr = 516.27, Z = 4, Dc = 2.568g/cm3, μ = 5.419 mm-1, F(000) = 1016, R = 0.0590 and Rw = 0.1279 for 1110 observed reflections (I > 2σ(I)). X-ray analysis shows that the asymmetric unit of the title compound contains two crystallographically unique Zn(Ⅱ) atoms which are connected through the bridging carboxylate oxygen atoms of the btec ligands and μ2-bridging oxygen atoms of water molecules to generate an infinite one-dimensional chain. The adjacent chains are linked together through the benzene rings of the btec ligands to form a two-dimensional polymeric network. The adjacent two-dimensional layers are further connected together by the benzene rings of btec ligands to give the final three-dimensional structure. The benzene rings act as pillars between two layers.