含席夫碱和酰胺单元的新型双杯[4]芳烃的合成

对叔丁基杯[4]芳烃-1,3-二醛基衍生物2与对叔丁基杯[4]-1,3-二酰肼衍生物4在稀释条件下进行“1＋1”分子间缩合反应, 高产率地合成了含席夫碱和酰胺单元的新型双杯[4]芳烃衍生物5. 所有新化合物的结构经元素分析、质谱、核磁共振谱等表征证实, 杯[4]芳烃单元均为1,3-桥联且采取锥式构象.     

Synthesis,structures, and electrocatalytic properties of phosphine-monodentate, −chelate,and -bridge diiron 2,2-dimethylpropanedithiolate complexes related to [FeFe]-hydrogenases

To further extend diiron subsite models of [FeFe]-hydrogenases, the various substitutions of all-carbonyl diiron complex Fe₂(μ-Me₂pdt)(CO)₆ ( A , Me₂pdt = (SCH₂)₂CMe₂) with monophosphines or small bite-angle diphosphines are studied as follows. Firstly, the monodentate complexes Fe₂(μ-Me₂pdt)(CO)₅{κ¹-P(C₆H₄R-p)₃} [R = Me ( 1a ) and Cl ( 1b )] and Fe₂(μ-Me₂pdt)(CO)₅{κ¹-Ph₂PX'} [X' = NHPh ( 2a ) and CH₂PPh₂ ( 2b )] are readily afforded through the Me₃NO-assisted reactions of A with monophosphines P(C₆H₄R-p)₃ (R = Me, Cl) and diphosphines (Ph₂P)₂X (X = NPh, CH₂ (dppm)) in MeCN at room temperature, respectively. Secondly, the chelate complexes Fe₂(μ-Me₂pdt)(CO)₄(κ²-(Ph₂P)₂X) [X = NPh ( 3a ) and NBuⁿ ( 3b )] can be efficiently prepared by the UV-irradiated reactions of A with small bite-angle diphosphines (Ph₂P)₂X (X = NPh, NBuⁿ) in toluene. Thirdly, the bridge complexes Fe₂(μ-Me₂pdt)(CO)₄(μ-(Ph₂P)₂X) [X = NPh ( 4a ) and CH₂ ( 4b )] are well obtained from the refluxing solutions of A and diphosphines (Ph₂P)₂X (X = NPh, CH₂) in xylene. Rarely, the diphosphine-bridge complex 4b may be produced in low yield via the UV-irradiated solutions of A and the dppm ligand in toluene emitting at 365 nm. Eight new complexes obtained above have been well characterized by using element analysis, FT-IR, NMR (¹H, ³¹P) spectroscopies, and particularly for 1a , 1b , 2a , 3b , 4a , 4b by X-ray crystallography. Meanwhile, the electrochemical and electrocatalytic properties of three representative complexes 2a , 3a , and 4a with pendant N-phenyl groups are investigated and compared by using cyclic voltammetry (CV) in the absence and presence of trifluoroacetic acid (TFA) as a proton source, indicating that they are all found to be active for electrocatalytic proton reduction to hydrogen (H₂).     

Exact solutions and residual symmetries of the Ablowitz–Kaup–Newell–Segur system

The residual symmetries of the Ablowitz–Kaup–Newell–Segur(AKNS)equations are obtained by the truncated Painleve′analysis.The residual symmetries for the AKNS equations are proved to be nonlocal and the nonlocal residual symmetries are extended to the local Lie point symmetries of a prolonged AKNS system.The local Lie point symmetries of the prolonged AKNS equations are composed of the residual symmetries and the standard Lie point symmetries,which suggests that the residual symmetry method is a useful complement to the classical Lie group theory.The calculation on the symmetries shows that the enlarged equations are invariant under the scaling transformations,the space–time translations,and the shift translations.Three types of similarity solutions and the reduction equations are demonstrated.Furthermore,several types of exact solutions for the AKNS equations are obtained with the help of the symmetry method and the Bcklund transformations between the AKNS equations and the Schwarzian AKNS equation.     

可控粒径纳米Fe_3O_4的制备及其磁性研究

本文用空气氧化法,在可见光作用下,添加配合剂(EDTA、柠檬酸、酒石酸、谷氨酸)在室温进行了不同粒径纳米Fe3O4的制备及其磁性能研究。结果表明:在可见光作用下,随EDTA、柠檬酸、酒石酸、谷氨酸等配合剂的添加,得到纳米Fe3O4的粒径有所减小、分散性有所提高;配合剂及可见光共存时,体系反应速率得到提高,高的反应速率使纳米Fe3O4晶粒减小;控制适当的光照度和添加剂的量,室温可得到11.8~29.6nm的Fe3O4颗粒。不同粒径纳米Fe3O4分别呈现出超顺磁性、铁磁性特征。     

N503萃淋树脂吸萃铟的研究

考察了Ｎ_（５０３）萃淋树脂在盐酸、氢溴酸、硫酸－溴化钠体系中对铟的吸萃性能，研究了Ｎ_（５０３）萃淋树脂在氢溴酸体系中吸萃铟的动力学和机理，发现Ｎ_（５０３）萃淋树脂吸萃铟的反应按假一级反应进行，并符合Ｆｒｅｕｎｄｌｉｃｈ等温吸附式。吸附平衡和红外光谱研究发现Ｎ_（５０３）萃淋树脂吸附铟的反应按下式进行：     

Ultrasonic-assisted synthesis of monodisperse single-crystalline silver nanoplates and gold nanorings

A simple sonochemical route was developed for the crystal growth of uniform silver nanoplates and ringlike gold nanocrystals in a N,N-dimethylformamide solution. The platelike structures were generated from the selective growth on different crystal planes in the presence of poly(vinylpyrrolidone) and the ultrasonic-assisted Ostwald ripening processes. The silver nanoplates in solution served as the templates for the synthesis of ringlike gold crystals via a displacement reaction. Both the silver nanoplates and gold nanorings were highly oriented single crystals with (111) planes as the basal planes.     

新型多重氮杂杯[4]芳烃衍生物的合成

对叔丁基杯[4]芳烃-1,3-二醛基衍生物1与水杨酰肼、烟酰肼、异烟酰肼反应, 合成了具有开链结构新型杯[4]多重氮杂衍生物2a～2c, 产率分别为88%, 85%和90%. 化合物1与乙二酰肼、丙二酰肼、己二酰肼反应, 得到具有桥联结构的新型杯[4]多重氮杂衍生物3a～3c, 产率分别为86%, 89%和90%. 新化合物的结构经元素分析、质谱、核磁共振谱等表征证实, 杯[4]芳烃单元均为1,3-取代且采取锥式构象.     

Synthesis, structures, and magnetic properties of the copper(II), cobalt(II), and manganese(II) complexes with 9-acridinecarboxylate and 4-quinolinecarboxylate ligands

To explore the relationships between the structures of ligands and their complexes, we have synthesized and characterized a series of metal complexes with two structurally related ligands, 9-acridinecarboxylic acid (HL(1)) and 4-quinolinecarboxylate acid (HL(2)), [Cu(2)(mu(2)-OMe)(2)(L(1))(2)(H(2)O)(0.69)](n) 1, [Cu(2)(L(1))(4)(CH(3)OH)(2)] 2, [Cu(3)(L(1))(6)(CH(3)OH)(6)].3H(2)O 3, [Mn(3)(L(1))(6)(CH(3)OH)(6)].3H(2)O 4, [Co(3)(L(1))(6)(CH(3)OH)(6)].3H(2)O 5, [Cu(L(2))(2)](n) 6, [Mn(L(2))(2)(H(2)O)](n) 7, and [Co(L(2))(2)(H(2)O)](n) 8. 1 is a three-dimensional (3D) polymer with an interpenetrating NbO type network showing one-dimensional (1D) channels, whereas 2 and 3 take bi- and trinuclear structures, respectively, because of the differences in basicity of the reaction systems in preparing the three complexes. 4 and 5 have trinuclear structures similar to that of 3. In 1-5, ligand L(1) performs different coordination modes with N,O-bridging in 1 and O,O'-bridging in 2-5, and the metal ions also show different coordination geometries: square planar in 1, square pyramidal in 2, and octahedral in 3-5. 6 has a two-dimensional structure containing (4,4) grids in which L(2) adopts the N,O-bridging mode and the Cu(II) center takes square planar geometry. 7 and 8 are isostructural complexes showing 1D chain structures, with L(2) adopting the O,O-bridging mode. In addition, the intermolecular O-H...N hydrogen bonds and pi-pi stacking interactions further extend the complexes (except 1 and 6), forming 3D structures. The magnetic properties of 2-7 have been investigated and discussed in detail.     

MULTI-PROBE MAGNEIC FIELD MEASURING SYSTEM WITH HIGH PRECISION

HIRFL magnetic field measuring system was built in October, 1983. There are 94 Hall probes on a detecting arm. The positioning device, which mainly consists of a detecting arm, a rotating ring and a fixed ring, is of a polar coordinate type. For 16KG magnetic field, the measuring repeatability of the system is better than ±5×10^－5, the measuring accuracy is about ±1×10^－4. The measuring rate is about 188 data per minute.     

不同快淬速度对Nd8Fe85Mo1B6磁性的影响

通过直接快淬制备了不同淬速的Nd₈Fe₈₅Mo₁B₆样品.由振动样品磁强计测量的结果发现,快淬速度对样品的磁性有很大的影响.对样品进行X射线衍射和热磁分析发现,随着淬速的增加样品中的TbCu₇相增多,同时软磁相的晶粒尺寸降低,认为样品的相组成和晶粒尺寸的变化是其磁性存在差异的原因. 关键词：