1—（5—溴—2—吡啶偶氮）—2—萘酚—6—磺酸与铁（Ⅱ）显色反应的研究及其应用

本研究了１－（５－溴－２－吡啶偶氮）－２－萘酚－６－磺酸（５－Ｂｒ－ＰＡＮ－Ｓ）与铁（Ⅱ）的显色反应，试验表明，在ｐＨ３－１０范围内铁（Ⅱ）与５－Ｂｒ－ＰＡＮ－Ｓ型成稳定的络合物，络合物在５５０ｎｍ和７５０ｎｍ有二个吸收峰，其表现摩尔吸光系数分别为２．３１×１０＾４和１．７７×１０＾４Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１。络合物组成比为铁（Ⅱ）：５－Ｂｒ－ＰＡＮ－Ｓ＝１：２，络合物稳定常数为１．８２     

Fe（Ⅲ）—TEA—5—Br—PADAP—H2O2体系中催化波的研究及其应用

在０．２ｍｏｌ·Ｌ＾－１ＮＨ４Ｃｌ－ＮＨ３·Ｈ２Ｏ底液中，（ｐＨ为９．２６），得到一个极为灵敏的Ｆｅ（Ⅲ）－ＴＥＡ－５－Ｂｒ－ＰＡＤＡＰ－Ｈ２Ｏ２配合吸附催化波，其峰电位为－０．７１Ｖ（ｖｓ．ＳＣＥ）。铁浓度在１．８×１０＾－１０￣５．４×１０＾－６ｍｏｌ·Ｌ＾－１范围内与二阶导数波高呈线性关系。对该极谱波的性质进行了研究，证明是一种配合吸附催化波，并成功地应用于各类水样，钒催化剂中微量或痕量铁的     

2,6—二氯—4—溴偶氮胂光度法测定微量铀（Ⅵ）

本报道用了２，６－二氯－４－溴偶氮胂作显色剂测定微量铀（Ⅵ）的光度法。在Ｈ２ＳＯ４介质中，铀（Ⅵ与）２，６－二氯－４－溴偶氮胂形成１：２络合物，其λｍａｘ＝６４０ｎｍ；表观摩尔吸光系数为１．１×１０＾５Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１；铀的浓度在０．０－２２．０μｇ／ｍｌ内符合比耳定律。方法具有灵敏度高，选择性好，操作方便等特点并已用于废水及矿样中微量铀（Ⅵ）的测定。     

新显色剂2—[2—（6—甲基—苯并噻唑）偶氮]—5—二甲氨基苯磺酸与钯（Ⅱ）…

合成了新试剂２－［２－（６－甲基－苯并噻唑）偶氮］－５－二氨基苯磺酸，并研究了其与钯（Ⅱ）的显色反应。实验表明，该试剂与钯（Ⅱ）反在生成１：１蓝色水溶性络合物，在阴离面活性剂十二烷基硫酸钠（ＳＤＳ）存在下可稳定２４ｈ，其最大吸收波长为６１５ｎｍ，表观摩尔吸光系数为７．９４×１０＾４．ｍｏｌ＾－＾１．ｃｍ＾－＾１。钯量在０－０．８μｇ／ｍｌ范围内符合比尔定律。本法是目前测定钯（Ⅱ）的高灵敏度显色反应     

5—（4‘—溴—2’—羧基苯偶氮）罗丹宁与铜（Ⅱ）的显色反应及其应用

本报道了新显色剂５－（４’－溴－２’－羧基苯偶氮）罗丹宁的合成及在水溶液中的离解常数Ｋ１和Ｋ２，研究了该显色剂与铜（Ⅱ）的显色反应，在弱酸性时，试剂与铜（Ⅱ）形成摩尔比２：１的络合物，摩尔吸光系数为８．９×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。当铜的浓度在０～２．７ｍｇ／Ｌ的范围内符合比耳定律。用分光光度法测定了合金中铜的含量。     

新显色剂2—（5—硝基—2—吡啶偶氮）—5—二甲所苯胺与钯显色反应的研究及其…

用新合成的偶氮试剂２－（５－硝基－２－吡啶偶氮）－５－二甲氨基苯胺研究了光度法测定钯的反应条件。结果表明，在０．４５－１．２ｍｏｌ／Ｌ盐酸介质中，钯与试剂形成稳定的蓝色配合物，其最大吸收波长位于６２１ｎｍ处，表观摩尔吸收系数为９．４×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，配合成的组成为Ｐｄ：５－ＮＯ２－ＰＡＤＭＡ＝１：２，钯浓度在０－１０μｇ／１０ｍＬ范围内符合比尔定律。本方法是目前测定钯的高灵敏     

2—[2‘—（4’—甲基—苯并噻唑）偶氮]—5—二甲氨基苯甲酸与钯（Ⅱ）显色反应…

合成了新试剂２－［２＇－（４＇－甲基－苯并噻唑）偶氮］－５－二甲氨基苯甲酸，并研究了其与钯（Ⅱ）的显色反应。实验表明，在５０％乙醇介质中，该试剂与钯（Ⅱ）反应生成１：１络合物，其最大吸收波长为６９８ｎｍ，表观摩尔吸光系数为５．８３×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。     

钼（Ⅵ）—4—（2—苯并噻唑偶氮）邻苯二酚多元络合物显色体系及其应用…

ｐＨ４．５时，Ｍｏ（Ⅵ）与显色剂４－（２－苯并噻唑偶氮）邻苯二酚反应形成带负电荷的稳定紫红色１：２二元络合物。４０％丙酮水溶液中λｍａｘ为５６０ｎｍ，表观ε５６０为６．３３×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。     

1,3,3a,5—四苯基—3a,4,5,11—四氢—3H,6H—1,2,4—三唑并（ …

通过２，４－二苯基－２，３－二氢－１Ｈ－１，５－苯并二氮杂Ｚｕｏ与苯甲酰氯苯腙的（２＋３）环加成反应制备了标题化合物，用Ｘ射线单晶衍射仪测定了其晶体结构，晶体属正交晶系，空间群为Ｆｄｄ２．晶胞参数；ａ＝１．７６２８（４）ｎｍ，ｂ＝５．７５１２（１２）ｎｍ，ｃ＝１．０２２７ｎｍ，Ｖ＝１０．３６８（５）ｎｍ＾３，Ｚ＝１６，Ｄｃ＝１．２６２ｇ．ｃｍ＾－３，μ＝０．０７５ｍｍ＾－１，Ｆ（０００）＝４１６０     

新试剂1—（6—硝基—2—苯并噻唑）—3—（4—硝基苯）—三氮烯与锌的显？…

研究了新显色剂１－（６－硝基－２－苯并噻唑）－３－（４－硝基苯）－三氮烯（ＮＢＴＮＰＴ）与锌的显色反应，在非离子表面活性ＴｒｉｔｏｎＸ－１００存在下，ｐＨ１０．１～１０．８的Ｎａ２Ｂ４Ｏｒ－ＮａＯＨ缓冲溶液中，Ｚｎ＾２＋与试验能形成１：２的橙黄色配合物，最大吸收波长为４４６ｎｍ，同时在５２８ｎｍ处配合物表现有最大负吸收，其表观摩尔吸光系数分别为ε＝７．０３×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１和ε     

Alkenes in [2+2+2] Cycloadditions

Participation of alkenes and allenes in [2+2+2] cycloaddition reactions has attracted much attention recently. This version of the well‐established alkyne cyclotrimerization renders interesting products, such as cyclohexadienes and other polycycles, through cascade processes. Many mechanistic variations are observed when using certain metal complexes as catalysts. The frequent generation of stereogenic centers has prompted the development of efficient asymmetric versions. This Minireview summarizes the efforts reported to date on the use of double bonds as partners in [2+2+2] cyclotrimerizations.     

Supraleitung in Seltenerdmetall-Carbidhalogeniden des Typs SE2X2C2

Superconductivity in Rare Earth Metal Carbide Halides of the Type SE₂X₂C₂ The metallic nature of the carbide halides Y₂X₂C₂ is due to Y? C covalency. The superconductivity of the compounds is attributed to a pairwise attraction of conduction electrons by C₂-π* states at the Fermi level. The hypothesis is followed by experiments and band structure calculations. – Neutron powder diffraction reveals d(C? C) = 128(1) pm for Y₂Br₂C₂. X-ray single crystal investigations on Y₂Br₂C₂ and Y₂I_1.5Br_0.5C₂ show a characteristic variation of the coordination of the C₂ unit. Systematic changes of the average halide radius in Y₂(X,X′)₂C₂ (X,X′ = Br, Cl I, Cl and I, Br) lead to a monotonic increase of T_c = 2.3 K (X = Cl) via T_c = 5.05 K (X = Br) to a maximum T_c = 11.2 K for Y₂I_1.6Br_0.4C₂. No isotope effect for ¹²C/¹³C could be detected. Photoelectron spectra of Y₂Br₂C₂ (excitation energies between 40 and 140 eV) are compared with the results of band structure calculations (LMTO, E.H.). The electronic structure reveals two bands crossing the Fermi level. One of them has C₂-π*-Y-d_xz,yz character and exhibits a saddle-point at E_F. The other intersects the Fermi level with large dispersion and has exclusively Y-d character at the crossing point. The results are discussed with respect to theoretical models (van Hove singularity, local pairs and itinerant electrons).     

Metal Substitution in Layered Superconducting La2C2Br2

The effect of metal substitution in La₂C₂Br₂ by Lu (non-magnetic) and Ce (magnetic), respectively, on T_c was studied. The Lu substitution affects T_c, which decreases moderately with increasing amount of Lu. However Ce substitution affects T_c drastically, such that only 10% Ce substitution makes superconductivity disappear.     

Superconductivity in the intermetallic borocarbides YPd2B2C,YPt2B2C and LaPt2B2C

We report a detailed study of the thermodynamic properties of the conventional phonon-mediated superconductors YPd₂B₂C, YPt₂B₂C and LaPt₂B₂C. Our calculations conducted within the framework of the Migdal-Eliashberg formalism show that the experimental values of the critical temperature cannot be properly reproduced using commonly accepted value of Coulomb pseudopotential. Moreover, we proved that the values of universal ratios of conventional superconductivity appearing in the Bardeen-Copper-Schrieffer (BCS) theory are inconsistent with our results obtained from the investigated borocarbides. The observed differences are connected with the strong/medium-coupling and retardation effects existing in the studied systems.     

Synthesis of Gels in the System Na2O-ZrO2-SiO2

Gels have been synthesized in the SiO₂-Na₂O-ZrO₂ system and calcined at various temperatures up to 700°C. They have been studied by infrared absorption spectroscopy. The position of the asymmetric stretching frequency of the SiO₄ unit is used as a tracer of the homogeneity. It is shown that sodium increases the solubility of zirconium in the silica matrix as already observed in fused glasses.     

在乙二醇溶液中原位法制备纳米SnO2

乙二醇;锡配合物;溶胶 凝胶;纳米SnO2     

纳米ZrO2在O2/H2气中的表面效应

用ESR方法研究了一种纳米ZrO₂在普通H₂气中升温条件下的表面效应.ZrO₂上Zr³⁺的中心量约为1×10^-7mol/g.这些Zr³⁺中心是ZrO₂表面一些O^2-配位不饱和的Zr原子点位.在普通H₂气中,ZrO₂上的Zr³⁺中心数在温度低于400℃时变化很小.但在这一温度范围内从室温升温时,由ZrO₂表面羟基的H₂还原引起的F中心量随温度的升高而增加.温度高于400℃时,ZrO₂表面的Zr³⁺及F中心可与普通H₂气中存在的少量O₂气作用产生O₂^-,并伴随ZrO₂表面羟基的脱除而形成新的Zr³⁺.