MgCl2/Et3N催化合成α,β-不饱和氰代酯

用MgCl₂/Et₃N催化氰乙酸乙酯和芳香醛的缩合反应合成α,β-不饱和氰代酯, 反应可在室温进行. 产率87%～92%.     

LixNi0.8-yCo0.2ZnyOp的合成及电化学性能研究

A series of single-phase Li_xNi_0.8-yCo_0.2Zn_yO_p(0.96 ≤x≤ 1.10， 0 ≤y≤ 0.05， 2 ≤p≤ 2(1+y) ) (different in the y values) were synthesized by a two-step solid state reaction method， in which LiOH·H₂O， Zn-doped spherical Ni(OH)₂ and Co₂O₃ were used as the precursors. The ICP-AES analyses proved that the Zn-doped compounds synthesized had the nonstoichiometric form. The results of the XRD， SEM identified that the uniform particles of the as-prepared materials having a good layered structure were fine， narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as-prepared Zn-doped materials had not only a high capacity， but also a better cycling stability characterization than the un-doped one. The Li_1.06Ni_0.75Co_0.22Zn_0.03O_2.03 material has an initial reversible capacity as high as 160.5mAh·g^-1; and a first discharge efficiency 89.2%， and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.     

ZrW0.8Mo1.2O8立方相和正交相的微波合成及其表征

Both the cubic and orthorhombic ZrW_0.8Mo_1.2O₈ were prepared by precursor-microwave route. The cubic phase belonged to β-ZrW₂O₈ structure type and the orthorhombic phase was refined with the structural model of LT- ZrMo₂O₈ by the Rietveld method. The orthorhombic phase belonged to Pmn2₁ space group and the cell parameters were a_o=0.597 1(9) nm, b_o=0.730 6(1) nm, c_o=0.912 7(1) nm, R_p%=9.37; wR_p%=11.81. The TEM images were also given. The comparison was made between precursor-heated and precursor-microwave routes. Metastable polymorphic phase was favorably formed by the latter method.     

孕甾-5,20-二烯-3β-醇-3-O-β-D-吡喃木糖苷的合成

以妊娠双烯醇酮醋酸酯为起始原料, 经过6步反应以15.0%的总收率, 首次合成了孕甾-5,20-二烯-3β-醇-3-O-β-D-吡喃木糖苷. 关键反应为选择性还原α,β-不饱和酮, 夏皮罗反应, Koenig-Knorr 反应.     

钙钛矿型LaxSr1－xNi1－yCoyO3光电催化活性研究

用甘氨酸-硝酸盐燃烧合成法, 制备La_xSr_1－xNi_1－yCo_yO₃复合氧化物的陶瓷粉末, 对钙钛矿氧化物进行了XRD结构分析. 在通氧或不通氧下测试氧还原和氧析出的循环伏安曲线. 结果表明: 该氧电极具有双功能催化特性, 但不完全可逆. 利用汞灯作为激发光源, 进行几种水溶性染料和五种混合染料光解实验, 利用紫外-可见、红外以及人工神经网络光度法研究La_xSr_1－xNi_1－yCo_yO₃的催化性能. 结果表明: La_xSr_1－xNi_1－yCo_yO₃ (x＝0.7, 0.9, 1; y＝0.3, 0.75)复合氧化物都具有较强光催化特性; La_xSr_1－xNi_1－yCo_yO₃的光催化活性高于La_xSr_1－xNiO₃, 这与B位离子(Ni^2—, Co^2－)的电子构型有关; Co^2＋的加入可使La_xSr_1－xNiO₃的光催化活性有所提高.     

纳米钙钛矿LaxSr1-xFe1-yCoyO3复合氧化物的制备和表征

用甘氨酸-硝酸盐燃烧合成法，制备La_xSr_1-xFe_1-yCo_yO₃复合氧化物的陶瓷粉末，对该钙钛矿型氧化物进行了XRD、IR、紫外漫反射光谱及循环伏安曲线分析。结果表明：该复合氧化物粉体平均晶粒为15.3～29.8 nm,为立方和正交晶系。该氧电极具有双功能催化特性，但不完全可逆。对水溶液染料进行光解实验，利用紫外-可见、人工神经网络光度法研究La_xSr_1-xFe_1-yCo_yO₃的催化性能。结果表明：CO²⁺的加入可使La_xSr_1-xFeO₃的光催化活性有所提高，B位离子(Fe³⁺，CO²⁺)改变与加入，使La_xSr_1-xFe_1-yCo_yO₃(x=0.7，0.3；y=0.3，0.9，1)光催化活性高于La_xSr_1-xFeO₃。同时，对5种染料进行紫外光解，在0.75 h，脱色率大于91%，并为动力学一级反应。     

L-脯氨酸催化α-酮酰胺与甲基酮的不对称直接Aldol反应

用L-脯氨酸催化α-酮酰胺与甲基酮的不对称直接Aldol反应, 获得了不同光学活性的α-羟基酰胺, 产率在21%～99%之间, 对映选择性最高达到43% ee. 加成产物的结构用元素分析、红外光谱和核磁共振进行了表征.     

哒嗪酮类α1-肾上腺素受体拮抗剂的合成和生物活性研究

将苯(氧)乙胺和苯氧烷胺类α₁-肾上腺素受体拮抗剂中的苯(氧)乙胺、苯氧烷胺片段引入哒嗪酮类化合物中, 设计、合成了30个新的含哒嗪酮环的α₁-肾上腺素受体拮抗剂. 所有新化合物的结构均经¹H NMR, IR, HRMS确证. 生物活性测试表明28个目标物对α₁-肾上腺素受体有较好的拮抗作用(pA₂＞6.00), 化合物6o, 6p, 6q, 6v, 6x, 6y, 10c, 10d的pA₂值＞7.00.     

手性β-氨基醇催化α,β-不饱和酮的不对称环氧化反应

将以烯烃为原料通过Sharpless不对称双羟化等多步反应合成的8种手性β-氨基醇, 作为有机小分子催化剂, 用于催化α,β-不饱和酮的不对称环氧化反应．考察了影响对映选择性的催化剂结构、催化剂用量、氧化剂种类、溶剂、反应温度等因素．结果表明, 当催化剂用量为30 mol%、氧化剂为TBHP(叔丁基过氧化氢)、正己烷溶剂、在室温下、以(1S,2R)-(＋)-1,2-二苯基-2-甲氨基乙醇(3)作催化剂时, 所得环氧化物的对映体过量最高为70% ee, 产率最高为84%.     

Ce1－xNdxO2－δ固溶体的电子顺磁共振谱和阻抗谱的研究

利用溶胶-凝胶方法在800 ℃焙烧10 h后, 合成了固溶体Ce_1－xNd_xO_2－δ (x＝0.05～0.55), X射线衍射(XRD)测试表明固溶体已经形成立方萤石结构; 电子顺磁共振谱(EPR)研究表明在固溶体Ce_1－xNd_xO_2－δ中随着掺杂量x的增大, Ce^3＋离子含量减少, 说明掺杂Nd^3＋离子可以抑制Ce^4＋的还原; 交流阻抗谱的测量表明固溶体Ce_0.9Nd_0.1O_2－d 具有离子导电特性, 600和700 ℃时的电导率分别为4.25×10^－3和1.12×10^－2 S•cm^－1, 活化能为0.68 eV.     

P2O5对Li2O-SiO2-Al2O3-K2O-ZnO体系微晶玻璃析晶性能的影响

采用差热分析、X射线衍射及扫描电镜分析手段研究了P₂O₅对Li₂O-SiO₂-Al₂O₃-K₂O-ZnO体系牙科微晶玻璃析晶性能的影响, 并确定了P₂O₅的最适含量. 结果发现P₂O₅是该玻璃体系的有效成核剂, 未添加P₂O₅的玻璃体系成核密度低, 热处理后不能形成微晶体, 且主晶相为硅酸锂; 添加P₂O₅使玻璃在热处理后形成以二硅酸锂为主晶相的微晶玻璃. 该玻璃体系中添加4.5 wt%的P₂O₅可以得到较高体积含量和理想显微结构的牙科二硅酸锂微晶玻璃. P₂O₅含量为6 wt%的基质玻璃发生乳浊, 呈不透明的乳白色.     

有机锡配合物{[(n-C8H17)2Sn(O2CCH2CS2NC4H8O)]2O}2的合成，表征及晶体结构

The title complex {[(n-C₈H₁₇)₂Sn(O₂CCH₂CS₂NC₄H₈O)]₂O}₂ has been synthesized by the reaction of (morpholinylthiocarbamoylthio)acetic acid with the di-n-octyltin oxide in 1∶1 molar ratio. The complex was characterized by elemental analysis, IR and ¹H NMR. The crystal and molecular structure of complex was determined by X-ray single crystal diffraction. The crystal belongs to triclinic system with space group P1 and unit cell dimensions: a=1.201 5(9) nm, b=1.481 8(11) nm, c=1.894 1(14) nm, α=72.485(10)°, β=88.586(10)°, γ=66.893(9)°, and Z=1, μ=1.034 mm^-1, V=2.941(4) nm³, D_c=1.295 g·cm^-3, F(000)=1 196, R₁=0.058 8, wR₂=0.155 8. The complex is a centrosymmetric structure with a four-membered central endo-cyclic Sn₂O₂ unit in which two bridged oxygen atoms both connect with an exo-cyclic tin atom. The endo-cyclic tin atoms and the exo-cyclic tin atom are all five-coordinate and have coordination geometry of distorted trigonal bipyramid with an additional weak coordination carboxylate oxygen. Four carboxylate ligands are divided into two types. And two of them are monodentate and connecting to each of exo-cyclic tin atoms by using one oxygen atom, whereas the others bridge to each pair of exo-and endo-cyclic tin atoms utilizing one oxygen atom. CCDC: 277048.     

五齿环戊二烯(四齿环丁二烯)镍(Ⅰ)衍生络合阳离子[Ni(C5R5)(C4R′4)]+的电化学还原反应

用循环伏安法, 计时电位法和计时电流法, 在二氯甲烷、乙腈、四氢呋哺和丙瞵撑碳酸酯等不同溶剂中, 在铂电极上研究了五齿环戊二稀(四齿环丁二稀)镍(Ⅰ)夹心络合阳离子, Ni(h~5-C_5R_5)(h~4-C_4R'_4)~+, (R=H,CH_3,R'=CH_3,C_6H_5)的电化学行为。实验结果表明: 对于R=H, R'=C_6H_5; R=CH_3, R'=C_6H_5的镍络离子为单电子的可逆还原反应, 产物为“19价电子壳层”的镍中性络合物。但是, 对于R=H, R'=CH_3; R=CH_3, R'=CH_3的镍络离子则因伴随有化学后置反应-二聚化反应而为不可逆的电极反应, 电化学还原反应的可逆性在四氢呋喃中有减小的趋势。此外, 用电解的方法对还原反应产物作了进一步的研究, 并对二聚分子的结构式提出建议。     

A study of the thermal preparation of c-Cd4/3Ca2/3P4O12

The possibility of preparing binary cadmium-calcium cyclotetraphosphate (tetrametaphosphate) by means of thermal dehydration of the appropriate binary dihydrogen phosphate has been studied. The possible formation of this condensation product from the cadmium ions that are often present in the starting phosphoric compound used in the technological preparation of binary calcium cyclotetraphosphates (serving as new special pigments) would represent an important, hygienic method of binding them to an insoluble, less harmful cadmium compound. The maximum proportion of calcium in the binary product, as found by the authors of this paper, amounts to half of the cadmium constituent (in molar terms). That is why Cd_2/3Ca_1/3(H₂PO₄)₂·2H₂O was used as the starting material. Its dehydration was observed mainly by thermal analytical methods under quasi-isothermal-isobaric conditions. Isothermal calcination of the initial binary dihydrogenphosphate was carried out in an electric oven at various temperatures. The reaction products obtained were analysed by chromatography, IR spectroscopy, X-ray diffraction analysis, electron microscopy and AAS. The compositions of the calcinates were determined through extraction with solutions of inorganic compounds and with organic reagents.     

Study of CuO/Ce0.8Zr0.2O2 catalysts for low-temperature CO oxidation

Summary Copper oxide catalysts supported on Ce_0.8Zr_0.2O₂ were prepared via an impregnation method and characterized by XRD and H₂-TPR techniques. The catalytic activity of the samples for low-temperature CO oxidation was investigated by means of a microreactor-GC system. The influence of calcination temperature, calcination time and different CuO content on the catalytic activity was studied. TPR analysis indicated that well-dispersed CuO was responsible for the low-temperature CO oxidation. The results of the investigation showed that the calcination temperature and CuO loadings had larger influence than the calcination time.     

Deactivation of H3PW12O40/TiO2 catalyst used in the production of camphene

Summary The deactivation of the H3PW12O40 (HPW) catalyst supported on TiO2 used in the isomerization reaction of a-pinene and its regeneration were studied. The regeneration of the deactivated catalyst was carried out with an air flow at 300 and 500ºC, with an ozone-enriched oxygen flow at 150ºC and by extraction with solvent and acid treatment. Only the last treatment permitted to recover its activity restoring it in 48% of its initial value.     

三维结构多金属氧酸盐Ag4H3PTi2W10O40·16H2O的合成与表征

以Keggin型钛取代钨磷酸钾和醋酸银为反应物合成了1个新的多金属氧酸盐Ag4H3PTi2W10O40.16H2O(1),通过X射线单晶衍射分析确定了其晶体结构,通过ICP分析和热重分析确定了其组成,通过红外光谱和固体漫反射光谱表征了其性质.单晶结构分析表明,化合物1属于四方晶系,I4/m空间群,晶胞参数a=b=1.39905(13)nm,c=1.14358(18)nm,V=2.2384(5)nm3,Z=2,R1=0.0550,wR2=0.1590.化合物1中的Ag+均为六配位,每个Ag+同时与3个多阴离子上的2个端氧和4个桥氧配位形成{AgO6}单元,这些{AgO6}将该多阴离子连接成三维网络结构.     

Fe2O3掺杂Ce0.8Nd0.2O1.9固体电解质的结构与导电性能

采用溶胶-凝胶法合成SiO2含量小于50×10-6的Ce0.8Nd0.2O1.9(NDC)陶瓷粉体,并将少量Fe2O3加入到NDC体系中,讨论Fe2O3的掺杂对其微观结构及电性能的影响。通过X射线衍射(XRD)等手段对氧化物进行结构表征,交流阻抗谱(AC)测试电性能。研究表明,Fe2O3的掺杂显著提高NDC陶瓷材料的致密度;相比于NDC而言,加入Fe2O3后材料的晶界电导率提高约12倍,总电导率提高约6倍。     

Novel polyaniline-LiNi0.5La0.02Fe1.98O4 nanocomposites prepared via an in situ polymerization

Polyaniline (PANI)-LiNi_0.5La_0.02Fe_1.98O₄ nanocomposites were synthesized by an in situ polymerization of aniline in the presence of LiNi_0.5La_0.02Fe_1.98O₄ ferrite. The products were characterized by Fourier transform infrared (FTIR), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). FTIR spectra and XRD indicated the formation of the PANI-LiNi_0.5La_0.02Fe_1.98O₄ composites. AFM study was shown that the average size of samples was less than 100 nm and the ferrite particles had an effect on the morphology of composites. The nanocomposites under applied magnetic field exhibited the hysteresis loops of the ferrimagnetic nature, the saturation magnetization and the coercivity varied with the ferrite content. The bonding model for the composites was also studied.     

Effect of the addition of B2O3 and BaO-B2O3-SiO2 glasses on the microstructure and dielectric properties of giant dielectric constant material CaCu3Ti4O12

The effect of the addition of glassy phases on the microstructure and dielectric properties of CaCu₃Ti₄O₁₂ (CCTO) ceramics was investigated. Both single-component (B₂O₃) and multi-component (30 wt% BaO-60 wt% B₂O₃-10 wt% SiO₂ (BBS)) glass systems were chosen to study their effect on the density, microstructure and dielectric properties of CCTO. Addition of an optimum amount of B₂O₃ glass facilitated grain growth and an increase in dielectric constant. However, further increase in the B₂O₃ content resulted in its segregation at the grain boundaries associated with a reduction in the grain size. In contrast, BBS glass addition resulted in well-faceted grains and increase in the dielectric constant and decrease in the dielectric loss. An internal barrier layer capacitance (IBLC) model was invoked to correlate the dielectric constant with the grain size in these samples.