固载化金属酞菁(MPc)催化性能的研究——Ⅱ.MPc通过配位连接在硅胶上及其对O_2的活化作用

用有机合成的方法在硅胶表面连接上可与MPc配位的有机基团——(CH_2)_3N(C_2H_5)_2,MPc与之配位从而固载在硅胶上。UV-Vis漫反射光谱表明硅胶表面存在MPc。用ESR研究固载化MPc与O_2的作用,证明固载化CoPc、FePc可以与O_2作用产生O_2~-,CuPc则不能。

ISOLATION AND PROPERTIES OF MOLYBDENUM SERIES OF HETEROPOLY BLUE WITH KEGGIN STRUCTURE

The present paper reports the methods for preparing and isolating 8 kinds of 1:12 molybdenum series of heteropoly blue complexes KyHzXMo12O40 . nH2O (X=Si, P, As, Ge). The products were characterized by elemental analyses, potential titration, polarograms, cyclic voltammetry, IR spectra, visible-UV spectra, X-ray powder diffraction, XPS and P-31 NMR. The single crystal structure of 4-electron molybdenum-silicon heteropoly blue was measured and the positions of reduced molybdenum atoms were determined, i.e. they were located at Mo(3), Mo(7), Mo(8) and Mo(10). The experimental results show that the heteropoly blue remains Keggin structure. ESR spectra of heteropoly blue solids were first studied, from which it was found that the delocalization extent of 2-electron heteropoly blue and 4-electron heteropoly blue is smaller than that of 1-electron heteropoly blue. The study of thermal properties shows that the thermal stability increases with the increase of the reduction extent of heteropoly blue. The study of redox properties shows that the oxidizing power order of heteropoly blue changes in different mediums, and the polarographic half-wave voltage is found to be dependent on the electronegativity of the hetero atom linearly. It is found that the phosphorus heteropoly blue and arsenic heteropoly blue show a strong anti-acid property.

STUDY ON THE ACTIVE-CENTERS OF METHANE COUPLING CATALYSTS BY MEANS OF FLUORESCENCE EMISSION OF EU3+

Eu3+ ion was adopted as a probe to detect the probability of entrance of alkali elements into the crystal lattice of MgO, CaO and La2O3 by means of its characteristic emission. Based on the experimental data it is concluded that Li+ and Na+ ions can substitute Mg2+ and Ca2+ ions and only a small amount of K+ ion can enter into the lattice of CaO. Whilst Li+ ion can not enter into the lattice of lanthana. The conclusion of this investigation is in good agreement with that obtained by Lunsford by ESR studies.

STRUCTURE INVESTIGATION OF TI(OBU)4-ALET3 CATALYST BEFORE AND AFTER HEAT-TREATMENT

The catalyst structure of Ti(OBu)4-AlEt3 at different Al/Ti ratios before and after heat aging has been investigated from the data of UV, GC-MS, ESR and C-13 NMR spectra. The complex compounds formed by HTiEt2 and AlEt2(OBu) exist mainly in the catalyst solution, and no -OBu ligands linking with Ti atoms can be found at an Al/Ti ratio of four before heat aging. Many kinds of catalytic species with different size are formed after heat aging the catalyst at 110-degrees-C for 2 h. Dehydrogenation, accompanied by the valence change from Ti3+ to Ti2+, is observed during the aging process of the catalyst.

α-Keggin结构钼硅酸钾杂多蓝的合成与结构

本文用控制阴极电位电解还原方法,制得了以Si为杂原子的Keggin结构二电子、四电子杂多蓝K_2H_4[SiMo_2~ⅤMo_(10)~ⅥO_(40)]·12H_20(Ⅰ)和K_3H_5[SiMo_4~ⅤMo_8~ⅥO_(40)]·12H_2O(Ⅱ).通过IR,UV,极谱,XPS,ESR及单晶X射线衍射对所合成的杂多蓝进行了表征,确定了被还原的Mo(V)位置位于不同的边共用三金属簇内,测定结果表明,Keggin结构杂多阴离子还原后,八面体结构有轻微畸变,畸变程度随还原程度增大而增大。

一种润滑油极压抗磨剂的结构测定

本文采用红外光谱和电子自旋共振(ESR)等方法对一种润滑油极压抗磨剂硫化二(2-乙基已基)二硫代磷酸氧钼进行了结构鉴定。

新型可溶性酞菁铜(Ⅱ)衍生物的合成、结构及其成膜性

合成了两个新型取代酞菁铜(Ⅱ)衍生物:四-4-(2-甲氧基乙氧基-羰基)酞菁铜(Ⅱ)(A)和四-4-(2-正丁氧基乙氧基-羰基)酞菁铜(Ⅱ)(B),以元素分析、ESR、~1H NMR和FT-IR进行了表征。UV-vis光谱表明它们在氯仿溶液(10~(-5)～10(-6)mol/L)中主要以双分子缔合形式存在;X-射线粉末衍射表明配合物的分子以倾斜的方式相互平行排列;热重分析表明酞菁环引入有机基团后其热稳定性略有下降,且取代基越长,热稳定性越差。两个配合物的氯仿溶液在亚相(水)上的π-A曲线表明,它们均有明显的“气”液”“固”的变化过程,并能形成较好的单分子层膜。

针叶树越冬针叶光氧化与叶绿体超氧阴离子自由基

以Tiron为自旋探针,检出了越冬针叶叶绿体指示超氧阴离子自由基产生的TH~·ESR信号。此信号可由紫外辐射,也可由光合有效辐射产生。以单位叶绿素量为基数计算的信号强度比已报道的其它植物材料大2～3个数量级。红松叶绿体信号又大于其它针叶树。此信号可被外源SOD,抗坏血酸、乙醇和N_2抑制;随光照增加而增强,12月到次年5月期间又随时间而增强。上述结果表明红松针叶的冬季光氧化伤害与叶绿体中过量超氧阴离子自由基的产生有关。

越冬针叶有机自由基产额对低温和光照的反应

以越冬针叶树苗木针叶为材料在黑暗与强光照两种条件下用ESR波谱仪检测有机自由基信号强度对不同温度的反应。结果表明:1.越冬伤害越重,针叶有机自由基产额越高;2.有机自由基产额随温度下降而增加;3.光照对有机自由基产额有明显的增强作用,且此增强作用在0℃表现最明显;4.自由基清除剂维生素C对有机自由基的产生有明显的抑制作用。据此认为红松苗的越冬伤害和有机自由基的高产额有关。在自然界针叶有机自由基的高产额主要和冬季的强日照有关,但低温也有一定作用。

碱-碱土-稀土催化剂发射光谱的研究

用Eu~(3+)的发射光谱探讨了O~-物种的形成。对M/MgO、M/CaO体系(M为碱金属)的研究发现,Li~+、Na~+可进入MgO晶格;Li~+、Na~+、K~+可进入CaO晶格。由于Li~+不能进入La_2O_3晶格,故不能形成O~-物种,表明不同的催化剂体系在甲烷氧化偶联反应中会形成不同的活性中心。

STUDIES ON DEFECT STRUCTURE AND CATALYTIC PROPERTIES OF SN-MO OXIDES

The present work is devoted to the studies on relationship of structure and activity of Sn-Mo oxides by using XRD, ESR, IR, XPS, TEM and SEM. Eight samples with Mo/(Mo + Sn) rations: 0.0, 0.1, 0.2, 0.4, 0.6, 0.8, 0.9, 1.0 were prepared. On the basis of structure characterization, Sn-Mo oxides can be divided into three groups: Catalysts I with Mo/(Mo + So) less-than-or-equal-to 0.2, Catalysts II with 0.2 < Mo/(Mo + Sn) < 0.8, and catalysts III with Mo/(Mo + Sn) greater-than-or-equal-to 0.8. The solid solution of Mo5+ in tin oxide was formed and the cation vacancy was formed in catalysts I. The solid solution of Sn4+ in molybdenum oxide was formed in catalysts III. The lattice oxygen in catalysts III has higher mobility and reactivity than that in catalysts I. The catalysts III showed higher activity but lower selectivity than that of catalysts I.

ROLE OF H2S IN THE REDUCTION OF MOO3/AL2O3

MoO3/Al2O3 is reduced at least partly by sulfur which is formed from H2S in sulfidation with H2S/N2 mixture. SO2 formation during TPD of MoO3/Al2O3 with presorbed H2S provides evidence for the explanation.

LIGHT-ASSISTED OXIDATIVE DOPING OF POLYANILINES

A novel doping phenomenon of fully reduced polyaniline and poly-o-methyl-aniline, "light-assisted oxidative doping", was found for the first time. The doping reaction was followed by FTIR, UV-VIS, ESR and electrical conductivity measurements. It was shown that the fully reduced polyanilines in the form of HCl-salts undergo a spontaneous transition from an insulator or semiconductor to a conductor when exposed to air and light, and their final molecular chain structures are analogous to those found in HCl-doped common polyanilines.

COORDINATION CHEMISTRY AND SUPERCONDUCTIVITY

Analysing the coordination state of copper ions in cuprate superconductors, it is found that the larger the energy splitting between d(x2-y2) and d(z2) orbitals of Cu or the higher the energy of the d(x2-y2) orbital, the higher the Tc. Thus, appropriate coordination structures and strong-field ligands must be chosen for expanding the energy splitting and increasing the energy of the d(x2-y2) orbital when searching for new high-Tc superconductors. Summarizing the experimental results of ESR and XPS, it is considered that the [Cu2+ - O open-square-box 2- - Cu3+] resonance exists in cuprate superconductors and the electron field breathing mode is present. Analysing the mechanism and the relationship between the coordination state of Cu and Tc, we consider that the two dimensional Cu-O planes are responsible for the superconductivity of YBa2Cu3O7-y.

多组分钼酸盐催化剂的活性结构及其在丙烯氨氧化中的催化作用机理

用XRD,IR,Mossbauer,ESR,XPS和TPD研究了50％Ni_3Co_5Fe_xBiPK_(0.1)Mo_(12)O_(48.05+(3/2)x)-50％SiO_2催化剂的活性组分、催化行为和产物分布。结果表明,活性组分有Fe_2(MoO_4)_3,Bi_2O_3·3MoO_3,CoMoO_4和NiMoO_4。Bi_2O_3·3MoO_3是表面活性中心,起选择氧化作用;Fe_2(MoO_4)_3则起氧化还原的促进作用;CoMoO_4和NiMoO_4起结构稳定作用。还探讨了催化作用机理。