近期热点文章北大核心CSCD

关键词：Na＋活性·化学电源Operando研究方法Q. Li, Z. Liu, F. Zheng, R. Liu, J. Lee, G. Xu, G.Zhong, X. Hou, R. Fu, Z. Chen, K. Amine, J. Mi, S.Wu, C. P. Grey, Y. Yang. Identifying the Structural Evolution of the Na-Ion Battery Na2Fe PO4F Cathode,Angew. Chem. Int. Ed., 10.1002/anie.201805555.厦门大学杨勇教授和合作者采用原位高能XRD、固态NMR和DFT理论方法,研究了Na2FePO4F阴极材料循环过程中晶体结构的动态变化,发现存在两种Na＋晶格位点,但只有一种有电化学活性.化学电源中的Operando研究方法为揭示电极活性物质的构效关系和反应机理提供了有力工具.     

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正Size-Dependent Surface Phase Change of Lithium Iron Phosphate during Carbon Coating J.Wang,J.Yang,Y.Tang,J.Liu,Y.Zhang,G.Liang,M.Gauthier,Y.K.Chen-Wiegart,M.N.Banis,X.Li,R.Li,J.Wang,T.K.Sham,X.Sun Nature Commun.DOI:10.1038/ncomms4451发现LiFePO4包碳过程的界面相变与活性物质的粒径有关,纳米粒子的界面稳定性较高,而微米粒子在高温包碳过程中界面发生明显变化.     

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正Metal-Free Dihydrogen Oxidation by a Borenium Cation:A Combined Electrochemical/Frustrated Lewis Pair Approach E.J.Lawrence,T.J.Herrington,A.E.Ashley,G.G.Wildgoose Angew.Chem.Int.Ed.DOI:10.1002/anie.201405721以一种含硼杂环分子为电子传递媒介,催化有机介质中的氢氧化反应(HOR).Exfoliation of Layered Double Hydroxides for Enhanced Oxygen Evolution Catalysis F.Song,X.Hu Nature Commun.DOI:10.1038/ncomms5477     

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<正>Graphene,Related Two-Dimensional Crystals,and Hybrid Systems for Energy Conversion and Storage F.Bonaccorso,L.Colombo,G.Yu,M.Stoller,V.Tozzini,A.C.Ferrari,R.S.Ruoff,V.Pellegrini Science DOI:10.1126/science.1246501关于石墨烯用于能量转化与储存的综述.引用了138篇参考文献.     

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<正>Size-Dependent Electrocatalytic Reduction of CO2 over Pd Nanoparticles D.Gao,H.Zhou,J.Wang,S.Miao,F.Yang,G.Wang,J.Wang,X.Bao J.Am.Chem.Soc.DOI:10.1021/jacs.5b00046CO2还原反应Pd纳米催化剂的粒度效应.发现3.7nm时CO产率可达91.2%.     

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TiO2 Microboxes with Controlled Internal Porosity for High-Performance Lithium Storage X. Gao, G. Li, Y. Xu, Z. Hong, C. Liang, Z. Lin Angew. Chem. Int. Ed. DOI: 10.1002/anie.201506357 合成由TiO2纳米棒构成的纳米多孔结构,用作锂离子电池阳极材料,循环300周仍具有187 mAh?g-1的容量,且可20C高倍率放电. Highly Efficient Electrochemical Reduction of CO2 to CH4 in Ionic Liquid Using Metal-Organic Framework Cathode X. Kang, Q. Zhu, X. Sun, J. Hu, J. Zhang, Z. Liu, B. Han Chem. Sci. DOI: 10.1039/C5SC03291A 在碳纸表面沉积含Zn的金属有机框架（MOF）化合物,该电极可高效催化CO2电还原为CH4.     

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正A New Rechargeable Sodium Battery Utilizing Reversible Topotactic Oxygen Extraction/Insertion of CaFeOz(2.5≤z≤3)in An Organic Electrolyte M.Hibino,R.Harimoto,Y.Ogasawara,R.Kido,A.Sugahara,T.Kudo,E.Tochigi,N.Shibata,Y.Ikuhara,N.Mizuno J.Am.Chem.Soc.DOI:10.1021/ja411365z以CaFeO3为正极材料,充电时CaFeO3还原为CaFeO2.5,释放出来的O与Li+或Na+生成氧化物.     

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<正>Electrochemical Water-Splitting Based on Hypochlorite Oxidation K.M.Macounov觃,N.Simic,E.Ahlberg,P.Krtil J.Am.Chem.Soc.DOI:10.1021/jacs.5b02087碱性介质中ClO-在Pt电极表面氧化生成ClO·自由基,继而氧化H2O,产生O2和H2O2.间接实现水分解.     

Two New Sterols from Amoora yunnanensis

ThegenusAmooracomprisingabout25-3ospeciesisdistributedinIndiaandtheMalayPeninsula.SixspeciesaredistributedinYunnanprovince.Amoorayunnanensis(H.L.Li)C.YWu,ismainlydistributedintheSouthofYunnanl.AccordingtoPenningtonandStyles',Amooracannotbeconsideredasavalidgenus.UptonoWchemicalconstituentsforthisgenushavenotbeenreportedyet.lnourchemicalstudyonAmoorayunnanensis,tetTanortfiterPenoidsorprotolimonoidsthatwereconsideredaschemotaxonomicmarkersofthefamilyMeliaceae,werenotisolated.lnthispaper…     

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正Suppression of Lithium Dendrite Growth Using Cross-Linked Polyethylene/Poly(ethylene oxide)Electrolytes:A New Approach for Practical Lithium-Metal Polymer Batteries R.Khurana,J.L.Schaefer,L.A.Archer,G.W.Coates J.Am.Chem.Soc.DOI:10.1021/ja502133j将聚乙烯和聚氧乙烯的交联共聚物用作金属锂电池隔膜,不仅获得较高的离子电导率,还可抑制锂枝晶的生长.     

Non-equivalent water molecules in [Ni(H2O)6](ClO4)2 and in [Ni(D2O)6](ClO4)2 in the thermogravimetric investigations

The thermal decomposition of [Ni(H₂O)₆](ClO₄)₂ and [Ni(D₂O)₆](ClO₄)₂ were studied by thermogravimetric analysis (TG) and simultaneous differential thermal analysis (SDTA) at a constant heating rate. The gaseous products of the decomposition were on-line identified by a quadrupole mass spectrometer (QMS). In both cases the process of decomposition starts at ca. 410 K and is connected with removal of water molecules in a stepwise way; at the beginning the first water molecule is lost, then the second and at higher temperature the third one. The rest of the water molecules are lost in the temperature region of ClO₄⁻ decomposition. The energy of activation of the process was calculated in both cases.     

Calorimetric study and thermal analysis of [Gd4/3Y2/3(Gly)6(H2O)4](ClO4)6·5H2O and [ErY(Gly)6(H2O)4](ClO4)6·5H2O (Gly: glycin)

Two solid-state coordination compounds of rare earth metals with glycin, [Gd_4/3Y_2/3(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O and [ErY(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O were synthesized. The low-temperature heat capacities of the two coordination compounds were measured with an adiabatic calorimeter over the temperature range from 78 to 376 K. [Gd_4/3Y_2/3(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O melted at 342.90 K, while [ErY(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O melted at 328.79 K. The molar enthalpy and entropy of fusion for the two coordination compounds were determined to be 18.48 kJ mol⁻¹ and 53.9 J K⁻¹ mol⁻¹ for [Gd_4/3Y_2/3(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O, 1.82 kJ mol⁻¹ and 5.5 J K⁻¹ mol⁻¹ for [ErY(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O, respectively. Thermal decompositions of the two coordination compounds were studied through the thermogravimetry (TG). Possible mechanisms of the decompositions are discussed.     

利用温度跃升傅立叶变换红外原位分析技术对斯蒂酚酸碳酰肼和斯蒂酚酸氨基脲快速热解反应的研究

Flash pyrolysis of （CHZ）2TNR and （SCZ）2TNR was conducted by T-jump/FTIR spectroscopy under 0.1 MPa Ar atmosphere. The results show that eleven IR-active gas products obtained during flash pyrolysis process of the two title compounds are NO, CO, HCN, NH3, NO2, N2O, HNCO, HNO2, CO2, H2O and HCHO, of which NO and CO are the main gas products. The molar fraction of the individual product in the pyrolysis gas mixture was described as a function of time. At least some of the NO2, N2O and H2O can result from the oxidization reaction of NH3 during flash pyrolysis of （CHZ）2TNR. It can be concluded that the two compounds are not worthy of further in-depth consideration of the adoption in detonators as eco-friendly primary explosive, and should not be used as gas generation composition of automobile crash airbag system taking into account the toxicity.     

Complexes of N,N′,N′′-tris(2-hydroxypropyl)-1,4,7-triazacyclononane (L): Structures of [CuL](ClO4)(NO3), [CoL](ClO4)2, [ZnL](ClO4)2 and the catalytic activity of [MnL](ClO4)2 towards olefin epoxidation with hydrogen peroxide

Complexes of N,N′,N′′-tris(2-hydroxypropyl)-1,4,7-triazacyclononane (L), [CuL](ClO₄)(NO₃) (1), [CoL](ClO₄)₂ (2), [ZnL](ClO₄)₂ (3) and [MnL](ClO₄)₂ (4), have been synthesized and characterized on the basis of elemental analysis, electrospray ionization mass spectrometry, UV–Vis measurements and cyclic voltammetry. Crystal structures of the former three complexes, characterized by X-ray crystallography, show that these complexes are monoclinic with space group P2₁/n and P2₁/c. Each metal central in the complexes is six-coordinate with three N atoms of the macrocycle and three O atoms from the pendant hydroxypropyl arms, forming a distorted octahedral configuration. [MnL](ClO₄)₂ (4) is employed as catalyst in olefin epoxidation with H₂O₂. The final results indicate that complex (4) has good catalytic activity towards olefin epoxidation. Under mild conditions, the olefin conversion is moderate and epoxidation selectivity is 95–100%.     

Ni(II), Pd(II), Cu(II) And Zn(II) complexes with N-(2-Pyridyl)Carbonylaniline (L), Syntheses and X-Ray Crystal structures of [Cu(L)2(H2O)2](No3)2, [Cu(L)2(H2O)2](Clo4)2 and [Zn(L)2(H2O)2](Clo4)2

Reaction of the N-(2-pyridyl)carbonylaniline ligand (L) with Cu(NO₃)₂, Cu(ClO₄)₂, Zn(ClO₄)₂, Ni(NO₃)₂ and PdCl₂ gives complexes with stoichiometry [Cu(L)₂(H₂O)₂](NO₃)₂, [Cu(L)₂(H₂O)₂](ClO₄)₂, [Zn(L)₂(H₂O)₂] (ClO₄)_2, [Ni(L)₂(H₂O)Cl](NO₃) and PdLCl₂. The new complexes were characterized by elemental analyses and infrared spectra. The crystal structures of [Cu(L)₂(H₂O)₂](NO₃)₂, [Cu(L)₂(H₂O)₂](ClO₄)₂, and [Zn(L)₂(H₂O)₂](ClO₄)₂ were determined by X-ray crystallography. The cation complexes [M(L)₂(H₂O)₂] contain copper(II) and zinc(II) with distorted octahedral geometry with two N-(2-pyridyl)carbonylaniline (L) ligands occupying the equatorial sites. The hexa-coordinated metal atoms are bonded to two pyridinic nitrogens, two carbonyl oxygens and two water molecules occupying the axial sites. Both the coordinated water molecules and uncoordinated amide NH groups of the N-(2-pyridyl)carbonylaniline (L) ligands are involved in hydrogen bonding, resulting in infinite hydrogen-bonded chains running in one and two-dimensions.     

Structures Of Tetraammine Salts [Pt(NH3)4](N03)2, [Pd(NH3)4](N03)2, and [Pd(NH3)4]F2 H20

This contribution presents the results of a single crystal X-ray diffraction study of three ammine complexes of bivalent platinum and palladium: [Pt(NH₃)₄](N0₃)2, [Pd(NH₃)₄](N0₃)₂ and [Pd(NH₃)₄]F₂H₂O. The first two compounds are isostructural; metal atoms are located on inversion centers, all other atoms are in general positions. A three-dimensional framework is built from planar-square complex cations and nitrate ions joined by N-H...O hydrogen bonds. In [Pd(NH₃)₄]F₂H₂O, palladium atoms, as in the previous cases, are located on inversion centers, while oxygen atoms of water molecules are on the two-fold symmetry axis. A network of strong N-H...F and O-H...F hydrogen bonds linking the cations, anions, and crystallization water molecules is present in the structure.     

In[NC5H3(CO2)2](OH2)F: A new layered indium-organic framework material (NC5H3(CO2)2=2,6-pyridinedicarboxylate)

A new layered indium-organic framework material, In[NC₅H₃(CO₂)₂](OH₂)F has been synthesized by a hydrothermal reaction using In₂O₃, NH₄F, 2,6-NC₅H₃(CO₂H)₂ (2,6-pyridinedicarboxylic acid), HF, and water at 200 °C. Single-crystal X-ray diffraction was used to determine the structure of the reported material. In[NC₅H₃(CO₂)₂](OH₂)F has a novel layered structure consisting of InO₅NF polyhedra and the pyridinedicarboxylate organic linker. Detailed structural analyses with full characterization including infrared spectrum, thermogravimetric analysis, elemental analysis, exchange reactions for the coordinated water molecule, and gas adsorption experiments are reported.     

稀土配合物[Pr(C3H7NO2)2(C3H4N2)(H2O)](ClO4)3的标准生成焓及热分解动力学研究

合成了高氯酸镨和咪唑(C₃H₄N₂), DL-α-丙氨酸(C₃H₇NO₂)混配配合物晶体. 经傅立叶变换红外光谱、化学分析和元素分析确定其组成为[Pr(C₃H₇NO₂)₂(C₃H₄N₂)(H₂O)](ClO₄)₃. 使用具有恒温环境的溶解-反应量热计, 以2.0 mol•L^－1 HCl为量热溶剂, 在T＝(298.150±0.001) K时测定出化学反应PrCl₃•6H₂O(s)＋2C₃H₇NO₂(s)＋C₃H₄N₂(s)＋3NaClO₄(s)＝[Pr(C₃H₇NO₂)₂(C₃H₄N₂)(H₂O)](ClO₄)₃(s)＋3NaCl(s)＋5H₂O(1)的标准摩尔反应焓为Δ_rH_m^ө＝(39.26±0.11) kJ•mol^－1. 根据盖斯定律, 计算出配合物的标准摩尔生成焓为Δ_fH_m^ө{[Pr(C₃H₇NO₂)₂(C₃H₄N₂)(H₂O)](ClO₄)₃(s), 298.150 K}＝(－2424.2±3.3) kJ•mol^－1. 采用TG-DTG技术研究了配合物在流动高纯氮气(99.99%)气氛中的非等温热分解动力学, 运用微分法(Achar-Brindley-sharp和Kissinger法)和积分法(Satava-Sestak和Coats-Redfern法)对非等温动力学数据进行分析, 求得分解反应的表观活化能E＝108.9 kJ•mol^－1, 动力学方程式为dα/dt＝2(5.90×10⁸/3)(1－α)[－ln(1－α)]^－1exp(－108.9×10³/RT).     

Phase transitions and molecular motions in [Ni(ND3)6](ClO4)2

[Ni(ND₃)₆](ClO₄)₂ has three solid phases between 100 and 300 K. The phase transitions temperatures at heating (T_C1^h=164.1 K and T_C2^h=145.1 K) are shifted, as compared to the non-deuterated compound, towards the lower temperature of ca. 8 and 5 K, respectively. The ClO₄⁻ anions perform fast, picosecond, isotropic reorientation with the activation energy of 6.6 kJ mol⁻¹, which abruptly slow down at T_C1^c phase transition, during sample cooling. The ND₃ ligands perform fast uniaxial reorientation around the Ni-N bond in all three detected phases, with the effective activation energy of 2.9 kJ mol⁻¹. The reorientational motion of ND₃ is only slightly distorted at the T_C1 phase transition due to the dynamical orientational order-disorder process of anions. The low value of the activation energy for the ND₃ reorientation suggests that this reorientation undergoes the translation-rotation coupling, which makes the barrier to the rotation of the ammonia ligands not constant but fluctuating. The phase polymorphism and the dynamics of the molecular reorientations of the title compound are similar but not quite identical with these of the [Ni(NH₃)₆](ClO₄)₂.     

Thermal decomposition of polycrystalline [Ni(NH3)6](NO3)2

The thermal decompositions of polycrystalline samples of [Ni(NH₃)₆](NO₃)₂ were studied by thermogravimetric analysis with simultaneous gaseous products of the decomposition identified by a quadruple mass spectrometer. Two measurements were made for samples placed in alumina crucibles, heated from 303 K up to 773 K in the flow (80 cm³ min^?1) of Ar 6.0 and He 5.0, at a constant heating rate of 10 K min^?1. Thermal decomposition process undergoes two main stages. First, the deamination of [Ni(NH₃)₆](NO₃)₂ to [Ni(NH₃)₂](NO₃)₂ occurs in four steps, and 4NH₃ molecules per formula unit are liberated. Then, decomposition of survivor [Ni(NH₃)₂](NO₃)₂ undergoes directly to the final decomposition products: NiO_1+x, N₂, O₂, nitrogen oxides and H₂O, without the formation of a stable Ni(NO₃)₂, because of the autocatalytic effect of the formed NiO_1+x. Obtained results were compared both with those published by us earlier, by Farhadi and Roostaei-Zaniyani later and also with the results published by Rejitha et al. quite recently. In contradiction to these last ones, in the first and second cases agreement between the results was obtained.