盐酸雷尼替丁的共振光散射新体系研究及其分析应用

在酸性条件下,盐酸雷尼替丁、铬黑T和钼酸铵通过静电作用形成三元离子缔合物,使体系的共振光散射明显增强.据此建立了共振光散射测定盐酸雷尼替丁的新方法.在最佳条件下,体系的最大散射峰位于363 nm处.共振光散射增强的程度与盐酸雷尼替丁的浓度呈良好的线性关系.方法的线性范围在0.015～0.165 mg/mL,检出限为9.5×10-3 mg/mL.将该方法用于市售盐酸雷尼替丁片的测定,并与药典方法进行对照,证明两种方法之间无显著性差异.     

Synthesis and Structure of a New Mixed-polyoxometalate （W/Mo） Compound： H5K{[Co（H2O）5]2（H2Mo3.24W8.76O42）}·19H2O

One new polyoxometalate compound connected via cobalt/potassium cations,namely H5K{[Co（H2O）5]2（H2Mo3.24W8.76O42）}·19H2O 1,was prepared and characterized by ele- mental analysis and IR spectroscopy. Single-crystal X-ray diffraction analysis result reveals that anions of {[Co（H2O）5]2（H2Mo3.24W8.76O42）}6- in compound 1 are linked by potassium cations to form one- dimensional chain,based on which a three-dimensional network is further constructed with the help of hydrogen bonds. Crystal data： H67Co2KMo3.24O72W8.76,Mr = 3297.87,monoclinic,C2/c,a = 19.0126（10）,b = 16.6025（5）,c = 19.1908（10）A,β = 106.713（1）°,V = 5801.8（5） A^3,Z = 4,Dc = 3.755 g/cm^3,F（000） = 5961,μ = 18.730 mm^-1,R = 0.0569 and wR = 0.1437 （I 〉 2σ（I））.     

白钨矿结构的钨,钼酸盐晶体的光吸收边及其起因

比较了一些白钨矿结构的钨，钼酸盐晶体（如未掺杂的ＣａＷＯ４，ＰｂＷＯ４，ＣａＭｏＯ，ＰｂＭｏＯ４晶体）的透射光谱，发现这些晶体的光吸收边的相对位置用普遍认为的观点，即白钨矿结构的钨，钼酸盐晶体的光吸收边起源于具有Ｔｄ对称性的Ｗ（Ｍｏ）Ｏ＾２－４基团的电子从ｔ１轨道的２ｅ轨道的转移激发，不能给出了圆满阐释，而应代之以新的观点，作者认为这类晶体的光吸收可能起因于Ｄ２ｄ对称的Ｗ（Ｍｏ）Ｏ＾２－４基团内的     

Synthesis,crystal structures and properties of the new compounds K7–xAg1+x(XO4)4 (X = Mo,W)

Two new isostructural compounds, namely heptapotassium silver tetrakis(tetraoxomolybdate), K_7–x Ag_1+x (MoO₄)₄ (0 ≤ x ≤ 0.4), and heptapotassium silver tetrakis(tetraoxotungstate), K_7–x Ag_1+x (WO₄)₄ (0 ≤ x ≤ 0.4), have been synthesized and found to crystallize in the polar space group P 6₃mc (Z = 2) with the unit‐cell dimensions a = 12.4188 (2) and c = 7.4338 (2) Å for K_6.68Ag_1.32(MoO₄)₄ (single‐crystal data), and a = 12.4912 (5) and c = 7.4526 (3) Å for K₇Ag(WO₄)₄ (Rietveld analysis data). Both structures represent a new structure type, with characteristic [K1(X O₄)₆] `pinwheels' of K1O₆ octahedra and six X O₄ tetrahedra (X = Mo, W) connected by common opposite faces into columns along the c axes. The octahedral columns are linked to each other through Ag1O₄ tetrahedra along with the K2 and K3/Ag2 polyhedra, forming the polar rods (…Ag1O₄–X 1O₄–empty octahedron–Ag1O₄…). Ag1 is located almost at the centre of the largest face of its coordination tetrahedron and seems to have some mobility. The new structure type is related to the Ba₆Nd₂Al₄O₁₅ and CaBaSiO₄ types, and to other structures of the α‐K₂SO₄–glaserite family. The differential scanning calorimetry (DSC) and second harmonic generation (SHG) results show that both compounds undergo first‐order phase transformations to high‐temperature centrosymmetric phases.     

Ultrafast room-temperature reduction of graphene oxide by sodium borohydride,sodium molybdate and hydrochloric acid

Since graphene-based materials have shown great potential in many fields,it is important to explore ultrafast and high-efficient methods to synthesize reduced graphene oxide(rGO) using inexpensive reducing agents under mild conditions.Here,we reported a novel method for the ultrafast chemical reduction of graphene oxide(GO) at room temperature using sodium borohydride(NaBH₄),sodium molybdate(Na₂MoO₄) and hydrochloric acid(HCl).The reduction was carried out within 2 min.A series of characterization results revealed that the obtained reduced graphene oxide has higher reduction degree than that synthesized by NaBH₄ alone at high temperature.Moreover,rGO electrode based on the present reducing method exhibited a superior specific capacitance of 139.8 F/g at a current density of1 A/g,indicating that it can be used as electrode materials for supercapacitors.     

Mischkristallbildung im System CuMoO4/ZnMoO4

Mixed Crystals in the System CuMoO₄/ZnMoO₄ The existence of a complet solid solution serie Cu_1–xZn_xMoO₄ (0 ≤ x ≤ 1) is confirmed. Single crystals were obtained by chemical transport with different transport agents. The compositions and structures were characterized by EDX analysis, photometic analysis, and X‐ray investigations on polycrystallin powders and single crystals. The substitution behaviour of (Cu_1–xZn_x)O₆‐ and (Cu_1–xZn_x)O₅‐polyhedra is different and the reason for deviations from the Vegards rule are near x = 0.25.     

Phase Relations in the CoMoO4-CoV2O6-CoO System Quasi-Binary Line Co3V2O8-CoMoO4

The phase relationship in the pseudobinary Co₃V₂O₈-CoMoO₄ system have been determined by differential thermal analysis (DTA) and X-ray diffraction (XRD). A new compound Co_2.5 VMoO₈, stable up to 1080±5°C has been found in the system. The results obtained are presented in the form of a phase diagram. This revised version was published online in July 2006 with corrections to the Cover Date.     

Phase Relations in The System Al2(MoO4)3–V2O5

The phase equilibria established in the system Al₂ (MoO₄ )₃ –V₂ O₅ throughout the whole component concentration range up to 1000°C were investigated by DTA and XRD methods. The results are presented in the form of a phase diagram. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis, Structure, and Magnetic Properties of One Polyoxometalate (W/Mo) Compound: H8K{[Ni(H2O)5]2(H2Mo1.80W10.20O42)}Cl3·16H2O

One new polyoxometalate compound connected via nickel/potassium cations, H8K{[Ni(H2O)5]2(H2Mo1.80W10.20O42)}Cl3·16H2O 1, was prepared and characterized by elemental analysis and IR spectroscopy. Single-crystal X-ray diffraction analysis results reveal that clusters of [Ni(H2O)5]2(H2Mo1.80W10.20O42)}6-in compound 1 are linked by potassium cations to form one- dimiensional chains, based on which a three-dimensional network is further constructed via the hydrogen bonds of O…O and O…Cl. Magnetic measurements show that compound 1 has para- magnetic properties. Crystal data: H62Cl3KMo1.80Ni2O68W10.20, Mr = 3461.33, monoclinic, space group C2/c, a = 18.9291(19), b = 16.6758(17), c = 19.1064(19)(A), β = 106.6880(10)(, V = 5777.1(10) (A)3, Z = 4, Dc = 3.980 g/cm3, F(000) = 6250, μ = 21.574 mm(1, R = 0.0579 and wR = 0.1623 (Ⅰ ＞ 2σ(I)).