Hydrothermal Synthesis and Crystal Structure of a New Sandwich—type Molybdenum Phosphate

1 INTRODUCTION The synthesis of porous and open-framework transition metal phosphates has received great in- terest due to their various compositions and topolo- gyies, as well as their useful properties such as con- trollable size- and shape-selectivity, rigid frame- works and chemical/thermal stability[1]. Of these phosphates constructed from oxometal polyhedra and PO4 tetrahedron, the most interesting is the [MoV6P4X31]n－ (X=O, OH) family with the dimen- sionalities ranging from …     

A Novel Hybrid Solid Constructed from Tetramolybdate and Copper Complexes with Mixed Ligands: [{(Cu·phen)_2(tp)}{(Cu·phen·H_2O)_2(tp)}{Mo_4O_(14)}]

A novel copper molybdate with mixed ligands, [{(Cu·phen)2(tp)}{(Cu·phen·H2O)2(tp)}{Mo4O14}] (phen = 1,10-phenanthroline, tp = terephthalate) 1, has been hydrothermally synthesized and structurally characterized. The crystal belongs to monoclinic system, space group P21/c with a = 13.1711(7), b = 19.6132(10), c = 13.6910(7) , β = 117.6870(10)°, V = 3131.8(3) 3, Z = 2, C64H44Cu4Mo4N8O24, Mr = 1946.99, Dc = 2.065 g/cm3, F(000) = 1920, μ(MoKα) = 2.198 mm-1, R = 0.0810 and wR = 0.2012 for 4233 observed reflections (I > 2σ(I)). The structural analysis indicates that the title compound contains a discrete tetramolybdate cluster decorated with copper complex fragments and tp ligands bridging the clusters into a wave-like layer. The hydrogen bond- ing between adjacent layers further extends the compound into a 3-D framework.     

激光诱导击穿光谱技术定量分析SF_6中的痕量O

六氟化硫(SF_6)气体因其优良的绝缘和灭弧性能,被广泛应用于高压绝缘设备中。然而,当存在H_2O和O_2等杂质时,SF_6气体在局部放电等作用下分解成的低氟化物会进一步与杂质发生反应生成稳定的氟硫氧化物和氢化物,使得设备绝缘性能下降,危害电网安全,因此检测和分析SF_6中微水、微氧及其分解产物具有重要意义。采用激光诱导击穿光谱技术测量了SF_6中的痕量O含量。利用CaF2作为窗口材料,解决了窗口材料在不断腐蚀作用下引起的激发能量逐渐衰减以及窗口材料与SF_6气体击穿产物反应引入的污染影响测量结果的问题,消除了由激发条件改变引起的等离子体状态的变化;通过测量不同O含量的SF_6气体激光诱导击穿光谱,结合迭代小波分析对实测光谱进行基线校正和降噪处理,通过定标曲线获得了O元素检测限为38ppm。利用偏最小二乘法建立了稳定的定量分析模型,改善了定量分析模型的稳定性和精度。     

pH控制下3，5-二羧基苯氧乙酸-Cd(Ⅱ)配合物的合成及晶体结构

以3,5-二羧基苯氧乙酸(H3L)为配体与醋酸镉在不同pH条件下获得了2个Cd(Ⅱ)配合物[Cd(H2L)2(H2O)4](1)、[Cd(HL)]n(2),通过红外、X-射线单晶衍射等检测手段对所合成的化合物进行了结构表征。测定结果表明,这2个配合物分别为配位分子和三维配位聚合物,其结构的形成与水热条件的pH值密切相关。该结果对以pH值控制配合物结构提供了研究基础。     

CRDS-CARS-PLIF技术精确定量测量火焰OH浓度实验研究（英文）

在预混甲烷/空气燃烧的平面火焰炉上,采用脉冲式光腔衰荡光谱技术(cavity ring-down spectroscopy, CRDS)实现了对OH分子浓度的定量测量。根据光腔衰荡吸收光谱理论,选取OH的A₂Σ⁺-X₂Π(0,0)电子跃迁带中的P₁(2)吸收谱线构搭建了一套激光波长在308.6 nm的脉冲CRDS实验装置。脉冲CRDS装置中的衰荡光腔是由一对反射率为99.7%的高反射镜组成且其衰荡腔的腔长为270 cm,并测量空腔(光腔中无火焰)的衰荡时间为2.33μs。通过理论分析影响浓度精确测量的实验参数,分别采用平面激光诱导荧光(planar laser induced fluorescence, PLIF)、相干反斯托克斯拉曼散射(coherent anti-stokes Raman scattering, CARS)和脉冲CRDS三种技术精确测量OH的有效吸收长度、高温火焰的温度和有效的光腔衰荡时间。当在平面火焰炉上燃烧预混的甲烷(1.1 L·min^-1)和空气(15...     

A New Luminescent Complex Cd（Ⅱ）-xanthene-9-carboxylate: [Cd（L）2（H2O）]n

A new luminescent Cd(Ⅱ) coordination polymer, [Cd(L)2(H2O)]n 1 (HL = xan-thene-9-carboxylic acid), was synthesized hydrothermally and characterized by satisfactory elemental analysis, FT-IR spectra and single-crystal X-ray diffraction. The crystal is of orthorhombic system, space group P212121 with a = 6.4548(4), b = 13.0876(12), c = 27.466(2), V = 2320.3(3)3, C28H20CdO7, Mr = 580.84, Z = 4, Dc = 1.663 g/cm3, F(000) = 1168, μ = 0.990 mm-1, Flack parameter = 0.00(2), the final R = 0.0296 and wR = 0.0691 for 5301 observed reflections (I > 2σ(I)). 1 features a one-dimensional (1D) carboxylate oxygen-bridged inorganic chain, which is further connected by intermolecular hydrogen bonds into a three-dimensional (3D) framework. Moreover, compound 1 exhibits strong photoluminescence in the solid state at room temperature.     

Syntheses and Crystal Structures of two Ring—like {Mo18}Cluster Compounds

1INTRODUCTIONThepolyoxomolybdateshavebeenwidelyresearchedinmanyfieldssuchascatalysis,biology,medicineandmaterialsciencebecauseoftheirrichphysicalandchemicalproperties[1].Thoughmanypolyoxomolybdateshavebeenreported[2],furtherresearchisstillnecessaryforthestudyof搑eduction-oxidation-reconstitution?self-assemblyprocesses[3,4].Polyoxomolybdatesarenormallybuiltupundersuitableconditionsbyafewbuildingblockssuchas{Mo2},{Mo8}and{Mo9}inself-assemblyway[5,6].The{Mo18}clustershaveseveralstructuralty…     

谈建构主义理论与中学化学教学

建构主义是当代最为流行的学习理论,它为教师反思教学行为提供了一个全新的视角。本文介绍了建构主义的基本观点和主要教学模式,提出了在化学教学中促进学生意义建构的指导思想和具体做法。     

纳米无机巨簇分子的红外、拉曼光谱研究

本文报道了用红外、拉曼光谱对四类纳米无机巨簇分子进行了比较研究。     

烷基膦酸类萃取剂与喹啉类萃取剂N601协萃锗（Ⅳ）的琛

研究了盐析剂浓度和水相ＰＨ值对分配比Ｄ的影响。研究了烷基膦酸萃取剂Ｐ５０７和喹吉林 类萃取剂Ｎ６０１协萃锗的机理，并对萃取平衡常数和热效应进行了估算。