碱金属和三价Eu离子共掺杂的碱土钼酸盐荧光粉发光性能

采用固相法制备了用于白光LED的Eu3+和碱土离子(Li+,Na+,K+)共激活的钼酸盐荧光粉AMoO4(A=Ca,Sr).通过X射线衍射图片看出,Eu3+和Na+的掺入降低了晶格参数,同时衍射峰强度明显增加.本文研究了荧光粉的激发光谱和发射光谱.它的激发谱覆盖了从240nm到500nm的范围,在470nm处有一个激发峰,这说明它能够被GaN LED发出的蓝光有效激发.发射谱表明它能够发射峰值位于616nm和624nm的红光.实验研究了碱土离子的量(摩尔分数)对AMoO4:Eu3+发光性能的影响,0.25是最合适的掺杂量.反应时间和反应温度对发光性能也有很大的影响.搅拌均匀的反应物在800℃灼烧3h得到的样品发光强度最强.     

Structure Tuning of Bi2MoO6 and Their Enhanced Visible Light Photocatalytic Performances

Structure-tuning strategies for synthesis and modification of Bi₂MoO₆, a novel visible light photocatalyst, have progressed at a quick pace. The enhancement of photocatalytic performances has been obtained through several morphology controls including hierarchical structures and heterojunctional nanocomposites. In this article, various structure modifications and their structural advantages in photocatalysis will be reviewed. In the first section, the structures of Bi₂MoO₆ such as crystal structures, electronic structures, and band structures will be presented. In the second section, many controllable synthesis approaches for modification of Bi₂MoO₆, including solid-state reaction, co-precipitation, solvothermal, and hydrothermal methods will be introduced. In the last section, the enhancement of photocatalytic activity for Bi₂MoO₆ due to the structure tuning will be discussed. The comprehensive review will provide perspectives on the research of efficient photocatalysts under visible light irradiation.     

α1受体阻滞剂类药物与某些同多酸根的共振瑞利散射光谱及其分析应用

在酸性介质中,钼酸根、钨酸根等同多酸根与盐酸哌唑嗪(PRH)和甲磺酸多沙唑嗪(Dox)等α1受体阻滞剂反应形成离子缔合物时,会导致体系的共振瑞利散射(RRS)显著增强并出现新的RRS光谱,最大散射峰分别位于367 nm(钼酸根体系)和290 nm(钨酸根体系)。 PRH和Dox与同多酸根的反应产物具有相似的RRS光谱特征。 其反应的适宜酸度分别为pH值2.1～2.3(钼酸根-PRH体系)和pH值3.1～3.3(钨酸根-PRH体系)。 在一定浓度范围内,不同的反应体系RRS强度增强程度与药物浓度成正比,均可用于痕量药物的测定。 反应具有很高的灵敏度,不同同多酸对PRH的检出限(3σ/s)分别为4.76 μg/L(钼酸根-PRH体系)和9.88 μg/L(钨酸根-PRH体系)。 方法也具有较好的选择性,用于片剂和人尿液中的α1受体阻滞剂的测定,结果满意。 此外,本文还应用计算化学软件Gaussview3.07和Gaussian03W,采用密度泛函法,在B3LYP/6-31G基组水平上计算了盐酸哌唑嗪的电荷分布,对反应机理和RRS增强的原因进行了讨论。     

微波辐射法合成辅酶Q0

以商用3,4,5-三甲氧基苯甲醛(Ⅰ)为起始原料,通过两步反应,合成了辅酶Q0,总收率达43．8％：第一步反应中,采用微波辐射改进了黄鸣龙还原法,以75．3％的收率制得3,4,5-三甲氧基甲苯(Ⅱ)。第二步采用50％的双氧水为氧化剂,钼酸铵为催化剂,将Ⅱ直接氧化为辅酶Q0,收率为58．2％。辅酶Q0的结构经IR,^1H NMR和^13NMR确证。     

Synthesis, structure and magnetic properties of the one-dimensional bimetallic oxide [Cu(terpy)Mo2O7]

The hydrothermal reaction of Cu(CH₃CO₂)₂·H₂O, Na₂MoO₄ and terpyridine at 140 °C for 48 h yields [Cu(terpy)Mo₂O₇] (1), a bimetallic one-dimensional oxide. The structure consists of ruffled chains of edge- and corner-sharing {MoO₅} square pyramids, decorated with {CuN₃O₂} ‘4+1’ axially distorted square pyramids. The Cu(II) polyhedra are disposed so as to produce an alternating pattern of Cu-Cu distances across the {Mo₂O₂} rhombi of the chain of 6.25 and 6.82 Å. This structural feature is reflected in the magnetic properties which are characteristic of a dimer rather than a linear chain, consistent with an alternating antiferromagnetic Heisenberg chain.     

Pressure-induced structural and electronic transition in KTb(MoO4)2 through Raman and optical studies

Raman and optical absorption studies under pressure have been conducted on KTb(MoO₄)₂ up to 35.5 GPa. A phase transformation occurs at 2.7 GPa when the crystal is pressurized at ambient temperature in a hydrostatic pressure medium. The sample changes to a deep yellow color at the transition and visibly contracts in theα-axis direction. The color shifts to red on further pressure increase. The Raman spectral features and the X-ray powder pattern change abruptly at the transition indicating a structural change. The pressure-induced transition appears to be a property of the layer-type alkali rare earth dimolybdates. However, the color change at the transition in KTb(MoO₄)₂ is rather unusual and is attributed to a valence change in Tb initiated by the structural transition and consequent intervalence charge transfer between Tb and Mo.In situ high pressure X-ray diffraction data suggest that phase II could be orthorhombic with a unit cell having 3 to 4% smaller volume than that of phase I.     

Variable-Temperature and High-Pressure Micro-Raman Spectra of Inorganic Artists' Pigments: Crystalline Wulfenite,Lead(II) Molybdate(VI), PbMoO4

Variable-temperature (?150°C to 600°C) and high-pressure (up to ～5 GPa) micro-Raman spectra have been obtained for the mineral wulfenite [lead(II) molybdate(VI), PbMoO₄], a main constituent of the artists' pigment, orange molybdate. The spectra were quite similar in both the temperature and the pressure studies, except for broadening and shifting of some peaks. No phase changes were detected, although there is possibly some amorphization beginning at ～600°C. The photoacoustic IR spectrum in the 1950–450 cm^?1 region is reported for characterization purposes. The long-term stability of PbMoO₄ with respect to extreme changes in both temperature and pressure illustrates the importance of orange molybdate in artwork and protective coatings.     

Ag负载CdMoO4光催化剂的制备及其催化性能

采用硼氢化钠还原法制备了Ag负载CdMoO₄光催化剂。运用X射线粉末衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）等测试手段对催化剂的组成和结构进行了表征;采用紫外-可见漫反射光谱（UV-Vis DRS）和X射线光电子能谱（XPS）等技术对催化剂的光响应和表面状态进行了分析,考察了不同Ag负载量对CdMoO₄紫外光降解罗丹明B和可见光选择性氧化苯甲醇性能的影响。结果表明,与CdMoO₄相比,Ag/CdMoO₄具有更高的光催化活性。利用活性物种捕获实验探讨其光催化降解过程的反应机理,实验结果显示O₂^-·和·OH是光催化降解过程的主要活性物种。     

A One-dimensional Metallic Oxide Constructed from Molybdenum Clusters and Mn（Ⅱ）-[3-（2-pyridyl） pyrazole] Cationic Coordination Components

A new polyoxomolybdate compound [Mn II (L) 2 (Mo 8 O 26) 0.5 ] 2n (1,L=3-(2-pyridyl)pyrazole) has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectroscopy.The compound crystallizes in the triclinic system,space group P1 with a=10.063(4),b=11.554(5),c=11.554(5),α=88.89,β=74.839(4),γ=74.839(4)o,V=1249.8(9) 3,C 16 H 14 MnMo 4 N 6 O 13,M r=937.03,D c=2.490 g/cm 3,μ(MoKα)=2.521 mm 1,F(000)=898,Z=2,the final R=0.0390 and wR=0.0970 for 4000 observed reflections (I > 2σ(Ⅰ)).Single-crystal X-ray diffraction analysis results reveal that compound 1 owns a chain structure based on β-[Mo 8 O 26 ] 4anions,which are linked by Mn II (L) 2 units via the terminal oxygen atoms.     

酸蒸气水热法合成钒取代水合碱式钨钼酸锆纳米晶体及热收缩Zr(WMo)0.93V0.14O7.93化合物

研究了酸蒸气水热法(ASH)合成VWMo.H2O时,酸蒸气源溶液的浓度,反应温度,填满度与反应时间等4个因素对晶体成核和生长两个阶段的影响。确定了以上4个影响因素的优化匹配条件,制备了VWMo.H2O纳米晶棒,并且对产物进行了表征。HCl-ASH法和HNO3-ASH法合成的VWMo.H2O化学式分别为Zr(WMo)0.93V0.14O6.93(OH0.92Cl0.08)2.(H2O)2和Zr(WMo)0.93V0.14O6.93(OH)2.(H2O)1.64;两者都与ZrMo2O7(OH)2.(H2O)2为同构化合物。以VWMo.H2O为前驱物在773K合成了立方热收缩化合物β-Zr(WMo)0.93V0.14O7.93。