INFLUENCE OF DIALKYLZINC IN RARE-EARTH TERNARY CATALYST ON THE COPOLYMERIZATION OF CARBON DIOXIDE AND PROPYLENE OXIDE

Rare-earth ternary catalysts Y（CCl3COO）3-ZnR2-glycerin were prepared for the copolymerization of carbon dioxide and propylene oxide （PO）, where dialkylzincs （ZnR2） were diethylzinc, di（n-propyl）zinc, di（n-butyl）zinc, di（i-propyl）zinc, di（i-butyl）zinc, di（s-butyl）zinc,respectively. The Y（CCl3COO）3-ZnR2-glycerin catalysts displayed the highest catalytic activity at the molar ratio of Y（CCl3COO）3：ZnR2：glycerin = 1：20：10. In the same copolymerization condition, catalysts containing dialkylzincs with branched alkyl group showed lower catalytic activity than that with primary alkyl group. For those catalysts including dialkylzincs with primary alkyl group, their catalytic activity decreases with increasing number of carbon atom in the alkyl group with the following sequence： Y（CCl3COO）3-ZnEt2-glycerin 〉 Y（CCl3COO）3-Zn（n- Pr）2-glycerin〉Y（CCl3COO）3-Zn（n-Bu）2-glycerin. However, the alkyl group in the dialkylzinc does not influence the insertion of PO into the propagation chain end.     

Synthesis and thermodynamic properties of a metal-organic framework: [LaCu6(μ-OH)3(Gly)6im6](ClO4)6

A metal-organic complex, which has the potential property of absorbing gases, [LaCu₆(μ-OH)₃(Gly)₆im₆](ClO₄)₆ was synthesized through the self-assembly of La³⁺, Cu²⁺, glycine (Gly) and imidazole (Im) in aqueous solution and characterized by IR, element analysis and powder XRD. The molar heat capacity, C_p,m, was measured from T = 80 to 390 K with an automated adiabatic calorimeter. The thermodynamic functions [H_T − H_298.15] and [S_T − S_298.15] were derived from the heat capacity data with temperature interval of 5 K. The thermal stability of the complex was investigated by differential scanning calorimetry (DSC).     

[M(en)3] (ndt)•H2O的水热合成、晶体结构和光学性能 ( M=NiⅡ, CoⅡ, MnⅡ and ndt=1,5-naphthalenedithiolate )

水热条件下，合成了三个新的配合物[Ni(en)₃] (ndt) ·H₂O 1, [Co(en)₃] (ndt) ·H₂O 2 和[Mn(en)₃] (ndt) ·H₂O 3。晶体结构通过X-射线单晶衍射进行了表征。三个配合物均属于单斜晶系，Cc空间群。[M(en)₃]²⁺阳离子、ndt阴离子和结晶水分子通过氢键自组装出相同结构的三维网。通过紫外-可见-近红外漫反射光谱对这三个配合物的光吸收性能和能带进行了测定。     

2′,3′-乙氧甲撑基腺苷5′-硫代磷酰氨基酸酯的合成和谱学分析

核苷磷酰氨基酸酯化合物是一类倍受重视的药物 ,特别是它可作为寡聚核苷酸的类似物用于反义药物 [1] .HIV逆转录酶是治疗艾滋病的有效靶点 ,目前普遍使用的抗 HIV核苷类似物中 ,2′,3′-双脱氧核苷 (dd Ns)具有良好的疗效 [2 ] .苯氧基取代的核苷 -磷酰氨基酸酯是 HIV逆转录酶的有效抑制剂[3 ] ,其药物毒性比 dd Ns低 ,但容易在体内被核酸酶水解 .由于硫代磷酸对核酸酶具有抵抗性 ,它可以抑制核酸酶对它的水解 [4 ] ,因此我们设计合成了核苷 5′-硫代磷酰氨基酸酯化合物 ,希望开发出一种全新的 HIV逆转录酶抑制剂 .由于分子中引入氨基…     

Tin Mediated Allylation of Aldimines with Allyl Bromide

SyntheticinterestsinhighlyfunctionalizedacyclicandcyclicamineshavecontributedtothewealthofexPerimentalmethodologydeveloPedfortheadditionofcarbanionstothecarbon-nitrogendoublebondofimines.Generally,organometallicreagentsorilltermedi-atesareusedascarbanionsandadditionofallylicorganometallicspeciestothenieconshtutesavaluablemethodforthesynthesisofhomoallylamines.'Amongthese,allyLlithium,'-magnesium,'-zinc,'-boraneandboronate,'-silaneand-stannane'havebeenusedforallylationofdriines.Ontheotherhand,…     

Bioisostere of Sulfonyl Moiety-The Synthesis of New ALS Inhibitors N-(Asymmetry Disubstituted Phosphoryl)-N'-(4,6-dimethoxypyrimidin-2-yl) Ureas

IntroductionAcetolactatesynthase(ALS)isthefirstcommonenzymeinthebiosyntheticpathwayforthebranched-chainaminoacidsvaline,leucineandisoleucine.Itisaveryeffectivetargetsiteforherbicidalaction,whichistheselectedmodeofactionasitisspecificforplantsanddoesnotaffectmammals.Sulfonylureaherbicidesareanewclassofherbicidesdiscoveredinthemid-l97O'sl.ItsmodeofactionhasbeenestablishedtobeinhibitorytowardALS2.Muchattentionhasbeenfocusedonthiskindofcompounds,sincetheyhaveexcellentactivity,ahighdegreeofseIe…     

2020 Roadmap on two-dimensional nanomaterials for environmental catalysis

This roadmap demonstrates a series of two-dimensional nanomaterials, such as graphene, black phosphorus, oxides, layered double hydroxides, chalcogenides, bismuth-based layered compounds, MXenes, metal organic frameworks, covalent organic frameworks, and others, for environmental catalysis.     

表面活性剂混合物水溶液中的囊泡形成

1:1烷基羧酸钠-溴化烷基三甲铵混合水溶液的浓度在cmc以上时, 能自发或超声分散形成一类新型混合表面活性剂囊泡(单层膜), 正负离子表面活性剂的突出囊泡形成能力以及不同表面活性剂结构组合变化所显现的多样特性, 皆预示出混合功能有序组合体研究的广阔前景。     

Study on multimers and their structures in molecular association mixture

Self-association system of(R)-1,3-butanediol in dilute carbon tetrachloride(CCl4)solution is studied as a model of molecular association mixture.Analysis methods including FSMWEFA(fixed-size moving window evolving factor analysis)combined with PCA(principal component analysis),SIMPLISMA (simple-to-use interactive self-modeling mixture analysis),and ITTFA(iterative target transformation factor analysis)are adopted to resolve infrared spectra of(R)-1,3-butanediol solution.Association number and equilibrium constant are computed.(R)-1,3-butanediol in dilute inert solution is determined as a monomer-trimer equilibrium system.Theoretical investigation of trimer structures is carried out with DFT(density functional theory),and structural factors are analyzed.     

The structure and electrochemical characteristics of La0.67Mg0.33 (Ni0.8Co0.1Mn0.1) x (x=2.5–5.0) multiphase alloys for nickel-metal hydride batteries

This paper presents results concerning structure and electrochemical characteristics of the La_0.67Mg_0.33 (Ni_0.8Co_0.1Mn_0.1) _x (x=2.5–5.0) alloy. It can be found from the result of the Rietveld analyses that the structures of the alloys change obviously with increasing x from 2.5 to 5.0. The main phase of the alloys with x=2.5–3.5 is LaMg₂Ni₉ phase with a PuNi₃-type rhombohedral structure, but the main phase of the alloys with x=4.0–5.0 is LaNi₅phase with a CaCu₅-type hexagonal structure. Furthermore, the phase ratio, lattice parameter and cell volume of the LaMg₂Ni₉phase and the LaNi₅ phase change with increasing x. The electrochemical studies show that the maximum discharge capacity increases from 214.7 mAh/g (x=2.5) to 391.1 mAh/g (x=3.5) and then decreases to 238.5 mAh/g (x=5.0). As the discharge current density is 1,200 mA/g, the high rate dischargeability (HRD) increases from 51.1% (x=2.5) to 83.7% (x=3.5) and then decreases to 71.6% (x=5.0). Moreover, the exchange current density (I ₀) of the alloy electrodes first increases and then decrease with increasing x from 2.5 to 5.0, which is consistent with the variation of the HRD. The cell volume reduces with increasing x in the alloys, which is detrimental to hydrogen diffusion and accordingly decreases the low-temperature dischargeability of the alloy electrodes.