二乙胺六氯化锡(IV)的合成、结构及介电开关特性（英文）

本研究合成了化合物二乙胺六氯化锡[Et_2NH_2]~+_2[SnCl_6]~(2-)(1)并对其进行了单晶X-射线衍射,DSC以及变温介电性能测试。研究结果表明,化合物1在高于370 K时发生了可逆一级相变,其相变过程与六氯化锡阴离子的各向同性旋转以及二乙胺阳离子的180°翻转运动有关。对应于该相变过程,化合物1可以实现高低介电状态转换,因而有望成为一种新型的高温分子基介电开关材料。     

CdS光化学修饰介孔TiO2及其增强的可见光催化活性

[目的]提高介孔TiO₂材料的光催化活性。[方法]采用蒸发诱导自组装法(EISA),以四氯化钛和钛酸丁酯为钛源,嵌段共聚物P123(EO₂₀PO₇₀EO₂₀)为模板剂,制备介孔TiO₂。用光化学修饰法将CdS掺进介孔TiO₂中,合成对可见光有较好响应的复合材料,并利用X射线衍射(XRD)、透射电镜(TEM)、原子吸收分光光度法(AAS)和光催化等手段对样品进行表征。[结果]XRD和TEM结果表明成功合成有序的六方介孔材料;AAS确定复合材料中Cd的含量为0.96mg/g;光催化于500 W氙灯下以2×10^-5mol/L次甲基蓝(MB)为模型污染物,结果显示CdS/TiO₂复合材料的可见光催化活性明显提高。[结论]光化学修饰法制备的介孔CdS/TiO₂复合材料可增强其可见光催化活性。     

含三联吡啶基团的聚三苯胺类电致变色薄膜的制备及性能研究

以4-甲酰基三苯胺和2-乙酰基吡啶为原料合成了配体TPAtpy，再与二价钴离子配位制备配合物Co (TPAtpy)₂，最后在ITO玻璃表面采用电化学聚合制备了两种电致变色薄膜poly-TPAtpy和poly-Co (TPAtpy)₂。由于Co (Ⅱ)金属离子与有机配体之间有较强的相互作用，金属配位聚合物具有更好的稳定性，poly-Co (TPAtpy)₂比poly-TPAtpy表现出更好的电致变色性质，poly-Co (TPAtpy)₂的光学对比度高达76.5％（750 nm），着色效率高达570.1 cm²/C，响应时间较短(着色时间：12.8 s；褪色时间1.8 s)。     

三核铜配合物[Cu3(TBSSB)2(BSA)2(bipy)2]·H2O的合成、晶体结构及性质研究

以牛磺酸缩5-溴水杨醛席夫碱（TBSSB）、5-溴水杨醛（BSA）、2,2''-联吡啶（bipy）为混合配体,合成了三核铜配合物[Cu₃（TBSSB）₂（BSA）₂（bipy）₂]·H₂O （1）,并对该化合物进行了元素分析、红外光谱、X-射线单晶衍射、光致发光光谱、固体漫反射光谱及分子轨道分析等表征。晶体结构分析表明,该化合物结晶属三斜晶系,Pī空间群,晶胞参数为a=10.031（2）Å,b=11.480（2）Å,c=12.913（3）Å,α=73.13（3）°,β=78.58（3）°,γ=75.24（3）°,V=1363.6（5）ų,Z=1,M_r=1533.30,Dc=1.867 g/cm³,F（000）=759,μ=4.236 mm^-1,S=0.921,R₁=0.0488,wR₂=0.0471（I > 2σ（I））,R₁=0.1812,wR₂=0.0546。Cu （2）离子与来自于两个TBSSB配体的两个氮原子和两个氧原子配位,形成正方形配位构型。Cu （1）离子与来自于一个2,2''-bipy的两个氮原子,TBSSB配体的一个氧原子,以及BSA的两个氧原子配位,形成四方锥形配位构型。该化合物分子通过O-H…Br分子内氢键和C-H…O分子间氢键相互连接形成三维超分子结构。研究发现该化合物能够发出蓝色荧光,它的带隙为2.19 eV。     

尿素辅助模板法合成介孔氮掺杂CeO2及其CO2捕获应用研究

以硝酸铈为前驱物,以尿素为助剂,采用一种简单的模板法合成了介孔氮掺杂CeO₂材料.利用X射线衍射仪(XRD)、吸附-脱附仪(BET)、透射电子显微镜(TEM)和傅里叶变换红外光谱(FT-IR)等设备对合成材料进行表征.多种测试结果证明:试验得到的纳米材料具有均一的介孔结构和较高的比表面积(124.8 m²·g^-1)并掺杂了氮元素.同时,测定了介孔CeO₂材料对于CO₂的吸附性能,并研究了氮掺杂对CeO₂材料的CO₂吸附性能的影响.结果表明:相比未掺杂氮的介孔CeO₂,氮掺杂的介孔CeO₂具有更好的CO₂吸附性能和循环吸附脱附性能.     

固氮酶催化机制及化学模拟生物固氮研究进展

综述了固氖酶催化机制及化学模拟生物固氮研究的最新进展和问题．根据 固氮酶在生理条件下,具有固氮和放氢双重功能的事实,认为在研究确定N₂络合和 还原位点的同时,也应确定H⁺还原成H₂的位点,才能为化学模拟生物固氮提供全 面信息,以指导化学模拟物的设计与合成;并提出组成固氮酶活性中心原子簇的 [Fes₃Fe₃]和[MoS₃Fe₃]可能分别是N2还原和H⁺还原位点的设想．此设想如经验证, 将会简化模拟物的化学合成,可望加速实现在较温和的条件下(<300c,<5066kPa (50 atm))将N₂还原成NH₃。     

含α，β-不饱和酮的新的环金属钌配合物的合成及其对HSO3-的识别

将 4-(2-吡啶基) 苯乙酮与 3-醛基-7-N, N-二乙基氨基香豆素缩合反应, 获得了具有α,β-不饱和酮结构的C,N-配体(1) ,再将该配体与[Ru(cycme) Cl₂]₂和 2,2''-二联吡啶反应, 得到了具有 α,β-不饱和酮的环金属钌配合物(2) ,并通过¹H NMR, MS 和紫外-可见吸收光谱表征了其结构．结果表明: 该配合物的最大吸收峰位于 475 nm,其摩尔消光系数达到 5.2×10⁴ mol^-1 ·L·cm^-1 ; 在 PBS 缓 冲溶液中, 可选择性识别 HSO₃^-, 对 HSO₃^-检测限为37 μmol /L.     

混合配体构筑的钌-铀酰异金属配位聚合物的合成和晶体结构及荧光性能

利用钌金属络合物离子和芳香有机二羧酸配体与铀酰离子在水热条件下反应，合成了一例新的异金属有机配位聚合物，也即[Ru(bipy)₃][(UO₂)₂(BDC)₃]·2H₂O，利用单晶X-射线衍射方法、粉末X-射线衍射方法、红外光谱对该配位聚合物结构进行了基本表征。该配合物是由金属配合物阳离子客体[Ru(bipy)₃]²⁺ 、二维蜂窝状平面结构的聚阴离子主体框架[(UO₂)₂(BDC)₃]_n^2-之间通过分子内和分子间C-H···O氢键的相互作用形成准三维超分子结构。此外，固体紫外-可见漫反射光谱测试表明此配合物具有半导体性质，是潜在的光电材料。固体荧光测量表明配合物表现出强烈的发光性能。     

钴铁氧体的溶胶凝胶燃烧法制备及其物性检测

通过溶胶凝胶燃烧法制备了钴铁氧体（CoFe₂O₄）纳米颗粒,并通过压片退火成型.XRD图谱显示样品成分无杂相.通过介电测试仪和振动样品磁强计测试了样品在室温下的介电性能和磁性能.试验结果表明,其介电常数和损耗都随着频率的变化而变化并展现出频散的行为,在低频范围内随着频率的增加而急剧减小,在高频范围内减小不明显.此外,其磁滞回线显示该类材料的饱和磁化强度、剩余磁化强度和矫顽力场分别为81.8 emu·g^-1,29.4 emu·g^-1和834.9 Oe.样品展现出良好的磁性能.     

一个新颖的双席夫碱配体衍生的双核镝(Ⅲ)配合物:合成、结构和磁性能研究

通过溶剂热方法合成了一个以2-[（2-羟基苯基）亚甲基联二腙]-N''-[（2-羟基苯基）亚甲基]-丙酰腙（H₃L）为配体的稀土镝（III）配合物[Dy₂（CH₃CN）₂（H₂O）₂（HL）₂（Cl）₂]·2CH₃CN,并通过单晶和粉末X-射线衍射、元素分析、红外光谱、热重分析、直流和交流磁化率对其结构和磁学性能进行了全面地表征。结构研究表明,该配合物结晶于单斜P2₁/c空间群,晶胞参数为a=0.78136（2）nm,b=1.81946（6）nm,c=1.63321（5）nm,β=97.365（3）°,V=2.32182（12）nm³,Z=2。在该配合物中,双去质子的HL^2-配体连接两个畸变的双帽三棱柱构型的Dy^III离子形成中心对称的双核结构。该配合物在零场下呈现出单分子磁体行为,其自旋磁矩翻转的有效能垒和指前因子分别为91.7 K和5.04×10^-6 s。     

Effects of Sr2+ substitution on the structural,dielectric, and piezoelectric properties of PZT-PMN ceramics

This study described the structural, dielectric, and piezoelectric behavior of Pb_1?x Sr _x [(Zr_0.52Ti_0.48)_0.95(Mn_1/3Nb_2/3)_0.05]O₃ ceramics (PSZT-PMN, x = 0, 0.025, 0.050, and 0.075), prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr²⁺-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary (MPB). Raman spectroscopy studies also confirm the existence of this MPB for x = 0.050. The piezoelectric strain coefficients (d ₃₃) value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr²⁺ concentration increases in the PZT-PMN ceramics.     

Structural phase transition, optical and pyroelectric properties of lead-free single crystals

0.14 at% Mn-doped 0.95(Na_1/2Bi_1/2)TiO₃-0.05BaTiO₃ (0.95NBT-0.05BT) lead-free single crystals were grown by a top-seeded solution growth method (TSSG). X-ray powder diffraction measurement showed that the as-grown single crystals exhibit rhombohedral perovskite structure with apparent distortion. With the increase of temperature, successive structural phase transitions occur in the Mn-doped 0.95NBT-0.05BT single crystals. After poling, apparent dielectric anomaly is induced accompanied by the increase of the character of diffuse phase transition and the decrease of the value of dielectric constant. The Mn-doped 0.95NBT-0.05BT single crystals exhibit complex domain structure, in which micro and macro domains coexist with statistically 4 mm symmetry. The Mn-doped 0.95NBT-0.05BT lead-free single crystals exhibit excellent piezoelectric and pyroelectric properties, which will lead to promising advance in piezoelectric and pyroelectric applications. The infrared-absorption band occurred around 630.6 cm^?1 can be assigned to the “stretching” normal vibration of [Na_1/2Bi_1/2]/Ti-O group. The three diffused Raman bands centered around 300, 560 and 800 cm^?1 can be attributed to F2g [TiO₆] bending vibration, A1g [TiO₆] stretching vibration and “soft mode” mixed by bending and stretching vibrations.     

Decompression-induced disorder to order phase transition in low-melting ionic liquid [OMIM][PF6]

In situ pressure-induced Raman spectral changes of 1-octyl-3-methyl imidazolium hexafluorophosphate （[OMIM][PF6]） have been investigated under the pressure up to 5.86 GPa at room temperature. The results indicated that [OMIM][PF6] experienced a phase transition at about 4.12 GPa during compression, and it was thought as a phase transition of liquid to a superpressurized glass. Upon decompression, from the obvious change of Raman spectra of [OMIM][PF6] at about 0.48 GPa, it could be inferred that a decompression-induced disorder to order phase transition in [OMIM][PF6] occurred. The phase behavior of [OMIM] [PF6] at low temperature under atmospheric pressure was also investigated in detail. The result showed that Raman spectra of [OMIM][PF6] varied slightly and no crystallization occurred upon cooling. These facts suggested that a disorder to order phase transition was induced by decompression in [OMIM][PF6], and [OMIM][PF6] served as a superpressurized glass under the pressure above 4.12 GPa, which was similar to the glassy state at low temperature.     

Investigation on the coordinate structures of the rare earth metal complexes with edta and cydta ligands

0　IntroductionThegreatattentionhasbeenpaidtorareearthorradioactiverareearthmetalcomplexesfortheirvariousbiologicactivi ties[1 3] .Forexamples,theradioactiverareearthmetal1 53SmⅢ com plexeswerewidelyusedfortumourtherapyofbrain ,liver,lung ,heartandbonetissues[4 5] ;forrareearthmetalEuⅢandTbⅢemitinguniquefluorescence ,theircompoundswereappliedfordiagnosesofvariousdiseases[6 ,7] ;forrareearthmetalGdⅢcontainingthemosthigh spinsingleelectrons,itscomplexeswereusuallyusedforcontrastagentsofmag…     

Synthesis and X-ray crystal structure of a new manganese 18-metallacrown-6

0　IntroductionThemetalionsinmetallamacrocylesformedbysupramolecularself assemblycantaketrigonal,square planar,andtetrahe dralconfiguration[1 ,2 ] .Metallacrownisaspecialclassofmetalla macrocyle,theyareanalogoustocrownethersinbothstructureandfunctionexceptthatthemetalionsarenowtakingthepositionsofcoordinationatomsincrownether[3,4] .Themetallacrownswithdifferentnumberof [M—N—O]repeatunithavedifferentcavitysizes,suchas 9 MC 3[5 7] ,12 MC 4 [4,8 1 4 ] and 15 MC 5 [1 5] .Thereportedazameta…     

Effects of temperature on hydrostatic pressure-induced FE-AFE phase transition in PbLa(Zr, Sn, Ti)O3 ceramics

Hydrostatic pressure-induced ferroelectricantiferroelectric (FE-AFE) phase transition and the pressure dependence of dielectric properties in La-doped Pb(Zr,Sn, Ti)O₃ ceramics were researched; the effects of temperature on hydrostatic pressure-induced FE-AFE phase transition and dielectric properties of the samples were studied. It was found that the temperature made the FE-AFE phase transition pressure decrease, and there existed the behavior of dielectric frequency dispersion and phase transition diffusion in the dielectric-pressure spectrum. These phenomena were very useful to enrich and develop the knowledge on the diffused phase transition behavior of polycomponent relaxor ferroelectric.     

糖蜜酒精废液脱钾树脂的解吸动力学

【目的】研究糖蜜酒精废液脱钾树脂BK-001中K~+的静态解吸过程。【方法】考察洗脱剂温度、浓度及树脂粒径对K~+解吸过程的影响,用动边界模型描述K~+的解吸过程。【结果】确定糖蜜酒精废液脱钾树脂BK-001中K~+的解吸过程为颗粒扩散控制,该反应的表观活化能为40.9kJ/mol,反应级数为1.19,表观频率因子为5.27×10~4 min~(-1),假二级动力学模型更适合描述K~+的解吸过程(R~20.995)。K+解析过程的总动力学方程式为1-3(1-F)~(2/3)+2(1-F)=5.27×104r20[H2SO4]~(1.19)e_((-4.09×10~4))/RT。【结论】脱钾树脂BK-001的解吸动力学方程为糖蜜酒精废液脱钾树脂的再生及钾盐资源的综合利用提供理论依据。     

Preparation,crystal structure and quantum chemical investigation of [Li(NTO) (H2O)]

[Li(NTO)(H₂O)₂] was prepared by mixing the aqueous solution of 3-nitro-1,2,4-triazol-5-one (NTO) and lithium hydroxide. The crystal structure of [Li(NTO)(H₂O)₂] was determined by single crystal diffraction analysis. The crystal is monoclinic, space group P2₁/n with crystal parameters of a = 0.742 0(2) nm, b = 0.344 9(1) nm,c = 2.490 6(3) nm, β= 94.89(1)°, Z = 4,D _c , = 1.799 g cm⁻³,V = 0.635 nm³, μ = 1.591 cm⁻¹, F(000) = 392. The finalR is 0.051. The MNDO MO calculation shows that the coordinate bonds of title compound possess certain extent of covalent character. O₂ atom of NTO anion is bonded to Li atom; the nitro group will be lost first when NTO is decomposed.     

Mechanisms of peroxynitrite-induced [Ca2+]i increase in single neuronal cell

The mechanism of peroxynitrite (ONOO⁻)-induced [ca²⁺]_i increase in single MN9D cell (Dopaminergic neuroblastoma cell line) was studied by using Fura-2 microfluorometric technique. The results show that ONOO⁻ caused a rapid increase of [Ca²⁺]_i when ONOO₋ was puffed to the cell. Removing Ca²⁺ from the bath or using calcium channel antagonist (CdCl₂, Nifedipine) greatly inhibited the [Ca²⁺]_i increase induced by ONOO⁻¹, suggesting that the opening of L-Ca²⁺ channel makes a great contribution to the [Ca²⁺]_i increase. The effect of sulfhydryl reductive agent (DTT) on ONOO⁻-induced [Ca²⁺]_i increase suggests that ONOO⁻-activating L-Ca²⁺ channel is partly related to its oxidative speciality.     

The giant magnetocaloric effect in Gd<Subscript>5</Subscript>Si<Subscript>2</Subscript>Ge<Subscript>2</Subscript> with low purity gadolinium

The giant magnetocaloric effect Gd5Si2Ge2 alloy was prepared with 99wt% low purity commercial Gd. Powder XRD and magnetic measurements showed that the Gd5Si2Ge2 alloy annealed at 1200℃ for 1h had a significant magnetic- crystallographic first order phase transition at about 270 K. The maximal magnetic entropy change is 17.55 J· kg^-1· K^-1 under a magnetic field change of 0-5 T. The distinct increase of magnetic entropy change belongs to the first-order phase transition from the orthorhombic Gd5Si4-type to the monoclinic Gd5Si2Ge2-type after high temperature heat-treatment.