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941.
Systematic Investigation of Reaction‐Time Dependence of Three Series of Copper–Lanthanide/Lanthanide Coordination Polymers: Syntheses,Structures, Photoluminescence,and Magnetism 下载免费PDF全文
Dr. Ju‐Wen Zhang Xiao‐Min Kan Bin‐Qiu Liu Guo‐Cheng Liu Dr. Ai‐Xiang Tian Prof. Xiu‐Li Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16219-16228
Three series of copper–lanthanide/lanthanide coordination polymers (CPs) LnIIICuIICuI(bct)3(H2O)2 [Ln=La ( 1 ), Ce ( 2 ), Pr ( 3 ), Nd ( 4 ), Sm ( 5 ), Eu ( 6 ), Gd ( 7 ), Tb ( 8 ), Dy ( 9 ), Er ( 10 ), Yb ( 11 ), and Lu ( 12 ), H2bct=2,5‐bis(carboxymethylmercapto)‐1,3,4‐thiadiazole acid], LnIIICuI(bct)2 [Ln=Ce ( 2 a ), Pr ( 3 a ), Nd ( 4 a ), Sm ( 5 a ), Eu ( 6 a ), Gd ( 7 a ), Tb ( 8 a ), Dy ( 9 a ), Er ( 10 a ), Yb ( 11 a ), and Lu ( 12 a )], and LnIII2(bct)3(H2O)5 [Ln=La ( 1 b ), Ce ( 2 b ), Pr ( 3 b ), Nd ( 4 b ), Sm ( 5 b ), Eu ( 6 b ), Gd ( 7 b ), Tb ( 8 b ), and Dy ( 9 b )] have been successfully constructed under hydrothermal conditions by modulating the reaction time. Structural characterization has revealed that CPs 1 – 12 possess a unique one‐dimensional (1D) strip‐shaped structure containing two types of double‐helical chains and a double‐helical channel. CPs 2 a – 12 a show a three‐dimensional (3D) framework formed by CuI linking two types of homochiral layers with double‐helical channels. CPs 1 b – 9 b exhibit a 3D framework with single‐helical channels. CPs 6 b and 8 b display visible red and green luminescence of the EuIII and TbIII ions, respectively, sensitized by the bct ligand, and microsecond‐level lifetimes. CP 8 b shows a rare magnetic transition between short‐range ferromagnetic ordering at 110 K and long‐range ferromagnetic ordering below 10 K. CPs 9 a and 9 b display field‐induced single‐chain magnet (SCM) and/or single‐molecule magnet (SMM) behaviors, with Ueff values of 51.7 and 36.5 K, respectively. 相似文献
942.
Assembly,Structures, and Properties of a Series of Metal‐Organic Coordination Polymers Derived from a Semi‐rigid Bis‐pyridyl‐bis‐amide Ligand 下载免费PDF全文
Xiu‐Li Wang Xiao‐Ting Sha Guo‐Cheng Liu Nai‐Li Chen Chun‐Hua Gong Yun Qu 《无机化学与普通化学杂志》2015,641(7):1274-1281
Four metal‐organic coordination polymers [Cd(4‐bpcb)1.5Cl2(H2O)] ( 1 ), [Cd(4‐bpcb)0.5(mip)(H2O)2] · 3H2O ( 2 ), [Co(4‐bpcb)(oba)(H2O)2] ( 3 ), and [Ni(4‐bpcb)(oba)(H2O)2] ( 4 ) [4‐bpcb = N,N′‐bis(4‐pyridinecarboxamide)‐1, 4‐benzene, H2mip = 5‐methylisophthalic acid, and H2oba = 4, 4′‐oxybis(benzoic acid)] were synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, elemental analyses, IR spectroscopy, powder X‐ray diffraction, and TG analysis. In complex 1 , two Cl– anions serve as bridges to connect two Cd‐(μ1‐4‐bpcb) subunits forming a dinuclear unit, which are further linked by μ2‐bridging 4‐bpcb to generate 1D zigzag chain. Complex 2 shows a 2D 63 network constructed by [Cd‐mip]n zigzag chains and μ2‐bridging 4‐bpcb ligands. Complexes 3 and 4 are isostructural 2D (4, 4) grid networks derived from [M‐oba]n (M = Co, Ni) zigzag chains and [M‐(4‐bpcb)]n linear chains. The 1D chains for 1 and the 2D networks for 2 – 4 are finally extended into 3D supramolecular architectures by hydrogen bonding interactions. The roles of dicarboxylates and central metal ions on the assembly and structures of the target compounds were discussed. Moreover, the thermal stabilities, photoluminescent properties, and photocatalytic activities of complexes 1 – 4 and the electrochemical properties of complexes 3 and 4 were investigated. 相似文献
943.
944.
超声波雾化辅助液体样品激光诱导击穿光谱技术研究 总被引:5,自引:1,他引:5
受到液体内部复杂环境因素的影响,LIBS技术在针对液体样品的成分检测分析的应用受到很大的制约.文章提出了一种由超声波雾化器件辅助,先将液体雾化成空气中密集的雾状小液滴,然后进行LIBS检测的新方法.并依据此思路实现了一套由超声波雾化器、Nd∶YAG激光器(1 064 nm)和ICCD探测器组成的检测系统.使用该系统对溶解有镁元素的水溶液样品进行了系统实验分析.实验发现,即使在相对较低的脉冲能量(30 mJ)下,该方法诱导的LIBS信号仍具有较长的寿命和较高的信背比.该方法对Mg元素的检测限能够达到0.242 ppm(10-6 g·g-1)量级.同时,文章还利用Ha线对等离子体的电子密度进行了计算,分析了等离子体演化的特点. 相似文献
945.
946.
Jianhua Zhou Yajun Ji Guiwang Zhao Chuanxiang Zhang Xiu Chen Tao Wang 《Acta Physico》2008,24(5):839-843
The influence of hierarchical porosity on electrocatalytic property was investigated with Pt nanoparticles supported on three types of carbon materials, namely, commercial Vulcan XC-72, ordered mesoporous carbon CMK-5, and hierarchical carbon aerogel (HCA). The electrocatalytic activity of carbon supported Pt nanoparticles was verified by cyclic voltammetry in H2SO4 and CH3OH solution. Pt/HCA presented superior performance with higher peak current (7.5 mA·cm−2) and electrochemical active area (128.0 m2·g−1). This could be attributed to the carbon aerogel with continuous but nonperiodical mesopore structure, which facilitated dispersion of Pt nanoparticles and mass transport around reactants and products. 相似文献
947.
Therearemanykindsofhairdyeswithdifferentformulae.Thekindwedeterminedcontainsthefollowingfiveconstituentsfl,4-phenylenediamine(P-PDA),4-aminophenol(P-APO),3-aminophenol(m-APO),1,3-benzendiol(m-BDO)and2,6-diaminopyridine(DAP).Withreversed-phasehigh-performanceliquidchromatography(RP-HPLC),someotherkindsofhairdyeshadbeendetermined"',butnotourkind.lnthispaperwedescribeaRP-HPLCmethodsuitabIefortheseparationandquantitativedeterminationofallthosefiveconstituentsinhairdyes.Analyseswereperf… 相似文献
948.
Photolysis of [Me2SiSiMe2)[C5H4Fe(CO2)]2with a series of bis(phosphine)ligands Ph2P(CH2)n PPh2(n=1-4) leads to the formation of the corresponding diiron complexes with intramolecular and intermolecular bis(phosphine) substitution.When these complexes were heated in refluxing xylene.only in the complexes with intermolecular bis(phosphine )substitution the thermal rearrangement reaction occurred. 相似文献
949.
Shu‐Sheng Zhang Rui Ren Xue‐Mei Li Qiang Li Xiu‐Yan Song Qing‐Li Wei 《Liquid crystals》2013,40(7):795-801
A series of novel compounds containing a 3‐fluoro‐4‐cyanophenoxy group were synthesized and fully characterized by IR and 1H NMR, and their mesomorphic properties were studied. Seven compounds exhibited enantiotropic nematic phases and three compounds exhibited monotropic nematic phases, as confirmed by differential scanning calorimetry and polarizing optical microscopy. Selected properties of the liquid crystalline compounds synthesized were calculated by ab initio methods at a HF/6‐31G level. The bond lengths, bond angles and dihedral angles of the fragments with the same structure change little between the compounds. All the compounds with a terminal alkoxy chain approached a planar structure. 相似文献
950.
An m-cycle system of order v and index λ, denoted by m-CS(v,λ), is a collection of cycles of length m whose edges partition the edges of λKv. An m-CS(v,λ) is α-resolvable if its cycles can be partitioned into classes such that each point of the design occurs in precisely α cycles in each class. The necessary conditions for the existence of such a design are m|λv(v-1)/2,2|λ(v -1),m|αv,α|λ(v-1)/2. It is shown in this paper that these conditions are also sufficient when m = 4. 相似文献