创新创业环境下本科生毕业论文指导的探索与体会

国家推动创新创业的时代大背景,对本科生毕业论文指导提出了比以往更高的期盼。论述了针对本科生毕业论文指导的7个方面的积极探索,以解决本科学生缺乏创新、动手能力差、分析能力欠缺、课本知识不会用、协同能力弱等问题。     

One—dimesional Infinite Chain Organotin Compounds： Synthesis and structural Characterization of Triphenyltin Thiazole—2—carboxylate and Triphenyltin 3—Pyridinylcarboxylate

Triphenyitin thiazole-2-carboxylate(1) and triphenyltin 3-pyridinylcar boxylate(2) were synthesized by the reaction of sodium thiazole-2-carboxylate or sodium 3-pyridinylcarboxylate with the triphenyltin chloride and their crystal structures were determined by single crystal X-ray diffraction analysis.In the structure of 1, the tin atom is five-coordinated in a distorted trigonal bipyramidal structure.Due to the presence of a close intermolecular Sn…S interaction distance of 0.3666nm,the structre can be described as a weakly-bridged on-dimensional chain compound.In the structure of 2,the tin atom is five-coordinated with bridging 3-pyridinylcarboxylate ligands N atom and resulting structure is one-dimensional chain compound.     

具有Cl…Cl作用的一维链状有机锡配合物——二(对氯苄基)氯化锡吡咯烷氨荒酸酯的合成、表征及晶体结构

A novel complex, chlorodi(p-chlorbenzyl)tin dithiotetrahydropyrrolocarbamate, has been synthesized. The crystal structure has been determined by X-ray single crystal diffraction. The crystal of the complex belongs to monoclinic with space group C2/c, a=3.070 0(19) nm, b=0.787 9(5) nm, c=2.374 9(15) nm, β=119.63(9) °, Z=8, V=4.993(5) nm³, D_c=1.515 g·cm^-3, μ=1.521 mm^-1, R₁=0.047 4, wR₂=0.097 2. The structure of the complex consists of discrete molecule containing five-coordinate tin atom in a seriously distorted trigonal bipyramidal configuration. The molecules are packed in the unit cell in one-dimensional chain polymer through a weak interaction between the chlorine atoms of the adjacent molecules. CCDC: 220743.     

三邻氯苄基锡-2-吲哚甲酸酯的合成、谱学性质和晶体结构(英)

The tri(o-chlorobenzyl)tin ester of 2-indolylcarboxylic acid has been synthesized and characterized by elemental analysis, IR and 1H NMR. The crystal structure has been determined by X-ray single crystal diffraction. The crystal belongs to triclinic with space group P1, a=1.020 0(16) nm, b=1.125 9(18) nm, c=1.321(2) nm, α=83.10(2)°, β=67.597(18)°, γ=84.83(2)°, Z=2, V=1.391(4) nm³, D_x=1.565 Mg·m^-3, μ=1.235 mm^-1, F(000)=656, R=0.049 2, wR=0.131 4. In this compound, the central tin atom is rendered four-coordinated in a tetrahedral structure. The resulting structure is a monomer containing Sn-O bond length of 0.205 4(4) nm. CCDC: 236286.     

双核有机锡(Ⅳ)配合物[Ph_3Sn(CH_3OH)O_2CC_6H_4CO_2(CH_3OH)-SnPh_3]·2CH_3OH和[Ph_3SnS_2CN(CH_2CH_2)_2NCS_2SnPh_3]·2CH_3OH的合成、表征和晶体结构

利用三苯基氯化锡和对苯二甲酸二钠、哌嗪荒酸二钠在甲醇中反应 ,合成了双核有机锡 (Ⅳ )配合物 [Ph3 Sn (CH3 OH)O2 CC6H4 CO2 (CH3 OH)SnPh3 ]·2CH3 OH (1)和 [Ph3 SnS2 CN(CH2 CH2 ) 2 NCS2 SnPh3 ]·2CH3 OH (2 ) .通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征 .用X射线单晶衍射测定了这两个化合物的晶体结构 .化合物 1为单斜晶系 ,空间群P2 1/n ,a =1.5 199(5 )nm ,b =0 .90 0 0 (3)nm ,c =1.82 0 6 (6 )nm ,β =113.970 (5 )° ,Z =2 ,V =2 .2 75 5(13)nm3 ,Dc=1.413g/cm3 ,μ =1.146mm-1,F(0 0 0 ) =980 ,R1=0 .0 35 3,wR2 =0 .0 6 0 6 .化合物 2为单斜晶系 ,空间群P2 1/c,a =1.5 0 6 6 (5 )nm ,b =1.0 875 (4 )nm ,c =1.35 42 (5 )nm ,β =91.6 14(5 )°,Z =2 ,V =2 .2 178(14)nm3 ,Dc=1.498g/cm3 ,μ =1.35 1mm-1,F(0 0 0 ) =10 0 8,R1=0 .0 40 1,wR2 =0 .1148.在 1和 2的晶体中 ,锡原子呈五配位畸变三角双锥构型 .配合物 1由未配位的甲醇分子通过氢键作用形成二维网状结构     

二苄基锡双(四氢吡咯荒酸酯)的合成、表征和晶体结构

Dibenzyltin bis(dithiotetrahydropyrrolocarbamate) was synthesized by the reaction of dibenzyltin dichloride with dithiotetrahydropyrrolocarbamate. The compound was characterized by elemental analysis, IR, ¹H NMR and MS. and the crystal structure was determined by X-ray single crystal diffraction. The crystal belongs to or-thorhombic with space group Pccn, a=2.1665(6)nm, b=0.9932(3)nm, c=1.1979(3)nm,α=90°,β=90°,γ=90°,Z=2,V=2.5777(12)nm³,D_c=1.529g·cm^-3,μ(MoKα)=1.330mm^-1,F(000)=1208,R₁=0.0341, wR₂=0.0627. In the crystals, the structures consist of discrete molecules in which the tin atom is six-coordinate in a distorted octahedron configuration. CCDC: 179919.     

离子对反相薄层色谱法分离三苯甲烷碱性染料

1 引言 三苯甲烷碱性染料是一类水溶性的阳离子染料。由于它们的分子结构非常相似,分离比较困难。本文用自制的GDX和硅胶G混合物制成的薄层板,采用离子对反相技术,分离了结晶紫、甲基紫、乙基紫、碘绿和孔雀石绿等五种三苯甲烷碱性染料,得到满意结果,方法简单、快速,对这类染料的鉴别和纯度分析都具有实用     

微波辐射下苯并噁唑基吡啶的合成

在微波辐射条件下,利用邻氨基酚和吡啶羧酸在多聚磷酸中的缩合反应,合成了2种苯并唑基取代吡啶 最佳反应条件为:450W辐射4min 相比于常规反应,反应时间大为缩短且产率令人满意     

Synthesis, Spectroscopic Properties and Crystal Structures of Dibenzyltin（IV） Dithiobenzoate and Chlorodibenzyltin（IV） Thiobenzoate

Two dibenzyltin(IV) complexes with thiobenzoate ligand, (PhCH2)2Sn(SOCPh)2 (1) and (PhCH2)2Sn(C1)SOCPh (2), have been synthesized by the reaction of dibenzyltin(IV) dichloride with thiobenzoic acid in the presence of organic base Et3N and characterized by IR, ^1H NMR spectroscopy and elemental analysis. Their crystal structures were determined by X-ray single crystal diffraction analysis. In the crystals of 1, the tin atom is six-coordinated in a distorted octahedron configuration. In the crystals of 2, the molecular packing in unit cell reveals that the two adjacent molecules are symmetrically linked to each other to form a dimer with intermolecular Sn…C1 distances of 0.3591 (2) nm and the tin atom is five-coordinated in a distorted trigonal bipyramid configuration.     

毛细管电泳用于形态分析

一种元素的生物可给性、环境行为和迁移性在很大程度上取决于它的形态。如不同的键合形式或氧化态，因此，作为元素物种鉴别和含量测定的形态分析变得越来越重要。毛细管电泳作为一种分离分析技术有许多优点可以满足形态分析的要求。本文从样品的预处理、毛细管电泳的修饰、进样方式、分离模式和检测等几个方面评述了毛细管电泳在形态分析中的应用。