4,4′‐Bipyridinium tetra­bromo­cadmate(II) with strong fluorescence

The title compound, (C₁₀H₁₀N₂)[CdBr₄], was synthesized via a hydro­thermal reaction. Its structure features discrete 4,4′‐bipyridinium cations and tetra­hedral [CdBr₄]²⁻ anions linked into ion pairs by single N—H⋯Br hydrogen bonds. Photoluminescent investigation reveals that the title compound displays a strong emission in the blue region, which may originate from π→π* charge‐transfer inter­actions of the 4,4′‐bipyridinium cations.     

Synthesis, crystal structure and characterization of a 2-D network organic-inorganic hybrid polymer with [α-BW12O40]5− as building blocks

A two-dimensional network compound [Ce(DMF)₄(H₂O)][α-BW₁₂O₄₀]·H₂O·(HDMA)₂ (HDMA = protoned dimethylamine, DMF = N,N-dimethylformamide) was synthesized from α-H₅BW₁₂O₄₀·nH₂O, Ce(NO₃)₃·6H₂O and DMF and characterized by IR, UV spectra and TG-DTA. The result of the X-ray single crystal diffraction indicates that the crystal is monoclinic, space group P2₁/n, with unit cell dimensional: a = 1.1983(3), b = 2.4216(5), c = 1.9517(4) nm, β = 92.91(3)°, Z = 4, R ₁ = 0.07710, wR ₂ = 0.1416. Structural analysis indicates that every [Ce(DMF)₄(H₂O)]³⁺ building block is surrounded by three adjacent [α-BW₁₂O₄₀]^5? polyanions, meanwhile, every [α-BW₁₂O₄₀]^5? polyanion interconnects with three neighboring [Ce(DMF)₄(H₂O)]³⁺ subunits, by making use of which two-dimensional network structure can be constructed. The result of thermogravimetric analysis manifests that the title compound has two-stage weight loss and the decomposition temperature of the title polyanionic framework is 560°C. The electrochemical analysis shows the title polyanion has three-step redox processes in the pH = 4–7 media.     

表面活性剂增敏阻抑动力学光度法测定痕量草酸

在稀盐酸介质中，微量草酸对H2O2氧化靛红的褪色反应有显著的阻抑作用，非离子表面活性剂Triton X-100对此体系有强烈的增敏作用，据此建立了表面活性剂增敏阻抑动力学光度分析测定微量草酸的新方法。方法的线性范围是0．005-0．50mg/L，检出限为0．005mg/L。方法简便，快速，灵敏度高，用于菠菜和尿样中草酸含量的测定，结果满意。     

成人及胎儿脏器组织中金属元素含量测定

采用火焰原子吸收法对１０例成人及８例胎儿脏器组织中Ｚｎ，Ｃｕ，Ｆｅ，Ｍｎ，Ｎｉ，Ｋ、Ｎａ，Ｃａ，Ｍｇ元素含量进行了测定，为了解人体脏器组织中元素含量，探讨其与健康的关系提供了有益的资料。     

MoO3-SnO2相互作用的研究

用沉淀法、浸渍法和机械混合物焙烧法制备了三组MoO_3-SnO_2催化剂。XDR, IR和ESR等研究表明: MoO_3-SnO_2之间存在明显的相互作用, 两组份间发生电子迁移现象, 导致Mo(Ⅵ)→Mo(Ⅴ)的价态变化, 产生pKa≤+3.3的表面酸位和甲醇选择氧化活性位。制备方法对这种相互作用以及样品的催化性能有明显影响。沉淀法所得样品中MoO_3可溶于SnO_2形成固溶体; 浸渍法则可发生钼离子向SnO_2体相的扩散; 机械混合物焙烧法在一定MoO_3含量下, MoO_3可在SnO_2表面形成近似单层分散。红外光谱中950 cm~(-1)的新吸收谱带可归因于表面上Mo(Ⅴ)=0振动。表面Mo(Ⅴ)位可能是催化剂表面酸位和甲醇氧化的活性中心。没有发现催化剂中Sn~(4+)价态有明显变化。     

含螯合配体的钕配合物的晶体结构

用NdCl_3,NaS_2CNEt_2和Et_4NBr为原料,在甲醇溶剂中反应,生成钕配合物,[Et_4N](Nd(S_2CNEt_2)_4]晶体,用X-射线衍射法测定了配合物的晶体结构。晶体属于单斜晶系,空间群P2_1/n晶胞参数,a=11.704(3)A,b=20.941(3)A,c=17.564(4)A,V=4242.2A~3,Z=4。结构经最小二乘方法修正后偏离因子为R=0.0564.在配合物钕离子是通过8个硫原子配位形成扭曲的NdS_3核的十二面体。井对配合物的红外线光谱和紫外可见光谱也进行了研究。     

含螯合配位体的M-Fe-S系列簇合物的合成,结构和性质研究(M=Mo,W)

本文总结报道了(1) [Et_4N]_3[Mo_2FeS_6(SCH_2CH_2S)_2],(2) [Et_4N]_3[W_2FeS_6(SCH_2CH_2S)_2]_2(3) {[Et_4N]_3[Mo_2FeS_6(SCH_2-CH_2S]_2}_4·CH_3CN和(4) [Et_4N]_4[Mo_2Fe_4S_9(SCH_2CH_2S)_2]四种簇合物的合成,结构和性质研究。在Nicolet R_3 System四圆单晶衍射仪上,用MoK_辐射收集数据,用SHELXTL程序,重原子法解出这些簇合物的晶体结构,用红外光谱、紫外可见光谱和穆斯堡尔谱对簇合物进行了物理性质的测定.同时用循环伏安法对簇合物的氧化还原特性也进行了研究,并结合量子化学计算探讨了簇合物的电子结构和性能之间的关系。     

Characterization of electrospray ionization mass spectrometry for N-diisopropyloxyphosphoryl dipeptide methyl esters

A systematic study of the fragmentation pattern of N-diisopropyloxyphosphoryl (DIPP) dipeptide methyl esters in an electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was presented. A combination of accurate mass measurement and tandem mass spectrometry had been used to characterize the major fragment ions observed in the ESI mass spectrum. It was found that the alkali metal ions acted as a fixed charge site and expelled the DIPP group after transferring a proton to the amide nitrogen. For all the N-phosphoryl dipeptide methyl esters, under the activation of a metal ion, the rearrangement product ion at m/z 163 was observed and confirmed to be the sodium adduct of phosphoric acid mono-isopropyl esters (PAIE), via a specific five-membered penta-co-ordinated phosphorus intermediate. However, no rearrangement ion was observed when a beta-amino acid was at the N-terminal. This could be used to develop a novel method for differentiating isomeric compounds when either alpha- or beta-amino acid are at the N-terminus of peptides. From the [M+Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters (DIPP Xaa1 Xaa2 OMe), the peaks corresponding to the [M+Na Xaa1 C3H6]+ were observed and explained. The [M+Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters with Phe located in the C-terminal, such as DIPPValPheOMe, DIPPLeuPheOMe, DIPPIlePheOMe, DIPPAlaPheOMe and DIPPPhePheOMe, had characteristic fragmentation. Two unusual gas-phase intramolecular rearrangement mechanisms were first proposed for this fragmentation. These rearrangements were not observed in dipeptide methyl ester analogs which did not contain the DIPP at the N-terminal, suggesting that this moiety was critical for the rearrangement.     

Covalently immobilized aminonaphthalimide as fluorescent carrier for the preparation of optical sensors

By replacing the hydrogen of the 4-amino group of a 4-amino-1,8-naphthalimide derivative with an N-acryloxyethyl group, the fluorophore has been covalently immobilized on an optical sensor surface by UV photopolymerization. The optical sensor obtained can be used for the determination of picric acid. The linear range and detection limit of the sensor are 9.80x10(-7)-1.96x10(-4) mol L(-1) and 7.1x10(-7) mol L(-1), respectively. Leaching of the fluorophore from the membrane is effectively prevented by covalent immobilization, resulting in a sensor with a relatively long lifetime. The response time of the sensor is short, and the reproducibility and reversibility are good. The sensor has been used for the indirect determination of the chloroquine content of pharmaceutical tablets.