煤浸出液中的阴阳离子测定及其与水煤浆成浆性的关系

用离子色谱法对十种煤(其灰分为3.03—8.20%)浸出液中的阴阳离子进行了测定,考察了它们与煤的成浆性的关系。计算机分析表明,矿物对煤成浆性的影响有两方面:一方面是可溶性矿物对成浆性的不利影响,另一方面是矿物密度对堆积效率的有利贡献。实验表明,硫酸根离子对煤成浆性的影响尤为突出,它综合反映了高价金属离子的总影响。     

PVC膜电极上的示波电位滴定法及其在药物分析中的应用

本文研究了用于示波电位滴定的PVC膜电极,成功地用于中和、络合及沉淀滴定,并探讨了它们在药物分析中的应用。所研究电极见表1。实验部分一仪器与试剂 SR-071型双踪示波器,213型铂片电极     

π键及大π键对正电集团和负电集团的作用——分子间引力的选择性

The selectivity of intermolecular force is caused by the special interaction between two adaptable groups on the molecules. π bond and conjugated π bonds such as benzene ring are negative charged groups,which may attract stongly positively charged H groups such as 3H in β-C_6H_6Cl_6, and repulse other ne- gatively charged groups such as-C=O(Q). Our experiments show that the reduced retention time tr of benzene on non- polar β-C_6H_6Cl_6 is much greater than that on polar fixed phases such as CH_3— —NO_2 in gas chromatography and that the het of solvation of β-C_6H_6Cl_6 in benzene is also much greater than that of the polar α-C_6H_6Cl_6 and γ-C_6H_6Cl_6. This can′t be explained by the usual Van de Waals′ force. It results from the selective intermoleccular force....     

有机溶剂化效应对多元配合物显色反应作用的研究 Ⅰ.有机溶剂对 M-CAS-CTMAB 体系显色反应微环境影响之初探

本文研究了有机溶剂加入后,表面活性剂增敏型体系微环境的变化。用核磁共振方法确定了有机溶剂分子与CTMAB胶束分子的作用部位。通过CTMAB溶液电导率测定及c.m.c值的测定,发现有机溶剂加入确实形成了一种新胶束。还研究了有机溶剂对显色反应速度的影响。并考察了体系微环境变化与相应显色液吸光度值的关系。我们的实验初步表明,有机溶剂的存在,改变了原有的CTMAB胶束,是增敏作用的重要因素,因而改变了发生显色反应的微环境。     

Synthesis,crystal structures and electrochemical properties of group 6 metal carbonyl anion complexes

A series of [M(CO)₅I]⁻ and [M₂(CO)₁₀I]⁻ anion complexes have been synthesized by the photochemical reaction of PhCH₂N(CH₃)₃I or FcCH₂N(CH₃)₃I (Fc=ferrocenyl) with M(CO)₆ (M = Cr, Mo or W), and characterized by elemental analyses, i.r., ¹H-n.m.r. and ¹³C-n.m.r. spectra in the case of the molybdenum and tungsten complexes. These complexes exhibit considerably different electrochemical behavior, when investigated by cyclic voltammetry. The crystal structures of [PhCH₂N(CH₃)₃][Cr(CO)₅I] and [FcCH₂N(CH₃)₃][W₂(CO)₁₀I] have been determined by X-ray diffraction, indicating that only weak contacts maybe exist between anions and cations by the I...H bond in the former, and there are no direct interactions between anions and cations in the latter.     

超导相Tl2Ba2CuO6的制备和晶体结构研究

The superconducting phase Tl_2Ba_2CuO_6 with onset T_C 85 K and zero resistivity at 61 K has been prepared. The unit cell is body-centred tetragonal, space group I_4/mmm, lattice parametrs a=0.3866(1) nm, c=2.3180(3) nm. The relation between structural features and its superconductivity was discussed.     

Urokinase片断的二级、三级结构预测及构效关系研究

urokinase(简称UK)属于絲氨酸蛋白酶,其一级结构已经测定。去掉前135个残基后得到的低分子量UK(LUK)氨基酸残基的顺序与糜胰蛋白酶、胰蛋白酶等絲氨酸蛋白酶十分类似。从二硫桥的配置来看LUK与糜胰蛋白酶比较接近,而UK对Lys侧链处肽键的专一性则和胰蛋白酶相近。在这一类酶中,起到活性中心作用的氨基酸为Ser195,His57及Asp102.在UK中此三个氨基酸都保留了下来。蛋白水解酶中起专一性作用的残基主要是     

Transition metal complexes with Girard reagent-based ligands

The ligand, salicylaldehyde Girard-T hydrazonium chloride, [H₂SalGT]Cl (1), and two complexes [Cu(HSalGT)X₂]·H₂O (X = Br(2); Cl(3)) were synthesized and their crystal structures were determined by single-crystal X-ray analysis. In the two isostructural complexes, the Cu(II) is located in a square-pyramidal environment, with the chelating ligand and one halogen atom in the basal plane and the second halogen in the apical position. The most apparent structural difference between the 1 and its complexes 2 and 3 is the orientation of the N(CH₃)₃ group: in 1, it is practically coplanar to the rest of the molecule, while in 2 and 3 it is oriented to the side of the axially bonded halogen, which can be explained by the C–H…X intramolecular interactions. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and electronic absorption spectra.     

Synthesis,crystal structure and ferro-magnetic interaction of a binuclear copper(II) complex with the 1,4-dinitro-2,3,5,6-tetracarboxylatobenzenic anion as bridging ligand

A binuclear complex [Cu₂(DTB)(DMF)₄(H₂O)]·2DMF (DTB = 1,4-dinitro-2,3,5,6-tetracarboxylatobenzenic anion; DMF = N,N-dimethylformamide) has been synthesized and its crystal structure determined by X-ray crystallography. In the complex Cu ion is located in a distorted square pyramidal environment with two oxygen atoms O(1) and O(3) from two carboxylate groups, another two oxygen atoms O(7) and O(8) from terminal ligands of two DMF molecules, and a fifth coordinated oxygen atom O(9) from the terminal ligand of one H₂O molecule, in which the O(8) atom is situated in the apex of the pyramid. DTB as bridging ligand coordinates two Cu ions through its four carboxylate groups. The variable-temperature magnetic susceptibility of the complex was measured in the 5–300 K range. The magnetic coupling parameter is consistent with a ferromagnetic exchange between the two copper(II) centers and the data fit a binuclear magnetic exchange model based on the Hamiltonian operator ( = -2J₁₂, ₁ = ₂= 1/2), giving the ferromagnetic coupling parameter of 2J = 1.80 cm^{- 1}. This is the first example of a tetracarboxylatobenzenic bridging complex exhibiting ferromagnetic interaction.     

Synthesis,crystal structure and property of a novel azide-bridged one-dimensional chain copper(II) complex with a dinucleating macrocyclic polyamine

An azide-bridged polymeric cationic chain complex, [LCu₂(N₃)₂]n(ClO₄)_2n ·n(H₂O)**, where L=the dinucleating macrocyclic ligand bis-p-xylylBISDIEN, has been prepared and characterized by x-ray crystallography, u.v.-vis and i.r. spectra, and by magnetic measurements. The structure consists of cationic azide-bridged [LCu₂(N₃)₂]²⁺ (unit) chains, non-coordinated perchlorate anions and crystallized water molecules. The azide anion is bound to two copper atoms in neighboring units with an end-to-end bridging mode. In each unit, the copper atoms have a different coordination geometry; Cu(1) is a four-coordinated, distorted square-planar geometry, whereas Cu(2) is a five-coordinated, distorted square-pyramid. The electronic spectra of the title complex differ in anhydrous and in aqueous MeCN solutions, indicating that dissociation and solvation occur in aqueous solutions. The characteristic i.r. absorptions of azides and perchlorates are described. Magnetic moments vary from 2.05 (B.M.) at 300K to2.01 (B.M.) at 80K, which suggests that very weak interactions exist between the metals.