期刊文献+
共找到281篇文章
< 1 2 15 >
每页显示 20 50 100
光催化剂Bi_(1-x)Gd_xVO_4的制备和表征及其光催化分解水 被引量:10
1
作者 王其召 蒋丽 +4 位作者 刘恢 袁坚 陈铭夏 施建伟 上官文峰 《物理化学学报》 SCIE CAS CSCD 北大核心 2009年第8期1703-1707,共5页
通过高温固相法合成了不同组分的光催化剂Bi1-xGdxVO4(x=0,0.1,0.2,0.3,0.5,0.7,0.9,1.0),并用X射线衍射(XRD)、紫外-可见漫反射光谱(DRS)、比表面积分析(BET)、扫描电子显微镜(SEM)对催化剂Bi1-xGdxVO4进行了表征和分析.XRD结果表明,在... 通过高温固相法合成了不同组分的光催化剂Bi1-xGdxVO4(x=0,0.1,0.2,0.3,0.5,0.7,0.9,1.0),并用X射线衍射(XRD)、紫外-可见漫反射光谱(DRS)、比表面积分析(BET)、扫描电子显微镜(SEM)对催化剂Bi1-xGdxVO4进行了表征和分析.XRD结果表明,在Bi1-xGdxVO4中存在两种结构,当0.3≤x≤1.0时,Bi1-xGdxVO4为四方晶系硅酸锆型结构;当x=0时,为单斜晶系白钨矿结构BiVO4;当0<x<0.3时,Bi1-xGdxVO4为单斜BiVO4和四方Bi1-xGdxVO4的混合物.负载了0.3%(w)Pt的Bi1-xGdxVO4在紫外光照射下能够分解纯水产生氢气,其中Bi0.5Gd0.5VO4的催化活性最好.Bi0.5Gd0.5VO4负载了助催化剂Pt、RuO2、Pt/Cr2O3、Rh/Cr2O3、Rh或Au后,在紫外光下可以光催化分解水生成氢气和氧气.其中负载RuO2、Pt/Cr2O3、Rh/Cr2O3能够完全分解水,负载Rh/Cr2O3时具有最好的光催化活性,并且可见光分解水的活性也得到了验证.在紫外光照射下,负载Rh/Cr2O3的Bi0.5Gd0.5VO4催化剂分解水产生氢气和氧气的速率分别为48.22和24.13μmol·h-1.研究结果表明,形成固溶体来调节价带和导带,是获得可见光响应光催化剂的一种可行的方法. 展开更多
关键词 光催化 bi1-xGdxVO4 可见光 水的分解 固溶体
下载PDF
N_2气氛烧结Bi_(1-x)Gd_xNbO_4微波介质陶瓷性能研究
2
作者 庞越 钟朝位 张树人 《压电与声光》 CSCD 北大核心 2008年第1期121-123,共3页
采用普通固相合成法制备了Bi1-xGdxNbO4微波介质陶瓷,研究了N2烧结气氛下,Gd部分取代BiN-bO4陶瓷中的Bi对其烧结性能及微波介电性能的影响。结果表明,不同Gd掺杂量的样品,相结构差别不大,均以低温斜方相为主晶相。随着Gd含量的增加,陶... 采用普通固相合成法制备了Bi1-xGdxNbO4微波介质陶瓷,研究了N2烧结气氛下,Gd部分取代BiN-bO4陶瓷中的Bi对其烧结性能及微波介电性能的影响。结果表明,不同Gd掺杂量的样品,相结构差别不大,均以低温斜方相为主晶相。随着Gd含量的增加,陶瓷样品的烧结温度升高,表观密度和相对介电常数均略有减小,品质因数与频率之积(Q×f)值也会发生变化。当x(Gd)=0.008时,900℃烧结的Bi0.992Gd0.008NbO4陶瓷样品具有较好的介电性能:介电常数rε=43.6(4.3 GHz),Q×f=14 288 GHz(4.3 GHz),谐振频率温度系数τf≈0。 展开更多
关键词 bi1-xgdxnbo4 微波介质陶瓷 气氛烧结
下载PDF
Sr_x(Na_(0.5)Bi_(0.5))_(1-x)Bi_4Ti_4O_(15)高温压电陶瓷的研究 被引量:2
3
作者 傅小龙 江向平 +2 位作者 陈超 李小红 涂娜 《中国陶瓷》 CAS CSCD 北大核心 2013年第9期17-21,共5页
采用传统固相法制备了Sr x(Na0.5Bi0.5)1-x Bi4Ti4O15(SNBT-100x,0≤x≤0.200)层状压电陶瓷。系统地研究了Sr2+对(Na0.5Bi0.5)Bi4Ti4O15基陶瓷的显微结构和电性能的影响。结果表明,所有陶瓷样品均为单一的正交铋层状结构相。适量Sr的掺... 采用传统固相法制备了Sr x(Na0.5Bi0.5)1-x Bi4Ti4O15(SNBT-100x,0≤x≤0.200)层状压电陶瓷。系统地研究了Sr2+对(Na0.5Bi0.5)Bi4Ti4O15基陶瓷的显微结构和电性能的影响。结果表明,所有陶瓷样品均为单一的正交铋层状结构相。适量Sr的掺入能明显改善陶瓷的机械性能和电性能。当x=0.100时,样品获得了最佳性能:机械品质因素Q m=3519,压电常数d33=20 pC/N,平面机电耦合系数k p=5.192%,厚度机电耦合系数k t=6.240%,相对介电常数εr=162,介电损耗tanδ=0.657%,居里温度T C=626℃。此外,热稳定性能研究显示SNBT-10陶瓷具有良好的压电稳定性,具有在高温领域下应用的前景。 展开更多
关键词 压电陶瓷 Srx(Na0 5bi0 5)1-xbi4Ti4O15 微观结构 介电性能 机电性能
下载PDF
Bi_(1.6)La_(0.4)Ti_2O_7薄膜的制备及性能研究 被引量:1
4
作者 陈如麒 徐初东 朱贵文 《中山大学学报(自然科学版)》 CAS CSCD 北大核心 2014年第1期78-82,共5页
采用化学溶液沉积法在ITO基片上制备不同退火温度的掺镧钛酸铋Bi1.6La0.4Ti2O7(BLT)薄膜。研究了其结构、介电性能、漏电流密度与外加电压I-V关系曲线和光学带隙。XRD射线衍射测试结果表明,经500、550、600℃1 h退火后的薄膜的主晶相为... 采用化学溶液沉积法在ITO基片上制备不同退火温度的掺镧钛酸铋Bi1.6La0.4Ti2O7(BLT)薄膜。研究了其结构、介电性能、漏电流密度与外加电压I-V关系曲线和光学带隙。XRD射线衍射测试结果表明,经500、550、600℃1 h退火后的薄膜的主晶相为烧绿石结构,无杂相生成,600℃时BLT薄膜衍射峰比其他两种温度的强。在1 kHz频率下测得的介电常数、损耗因子分别为114,3%;129,3%;194,6%。BLT薄膜的漏电流密度与外加电压关系曲线表明,BLT薄膜600℃的漏电流比550和500℃稍微减小。通过透射谱分析得到BLT薄膜的光学带隙几乎不受温度影响,均为3.7 eV。这些结果表明制备BLT固溶体薄膜较佳为退火温度600℃,具有较好的性能,在光电器件有良好的应用前景。 展开更多
关键词 化学溶液沉积法 bi1 6La0 4Ti2O7 光学带隙 介电
下载PDF
(1-x)Bi_4Ti_3O_(12-x)BaTiO_3高T_C压电陶瓷的结构与性能研究
5
作者 李博 高峰 +3 位作者 刘亮亮 许贝 曹宵 田长生 《压电与声光》 CSCD 北大核心 2011年第1期111-114,共4页
采用固相合成法制备了(1-x)Bi4Ti3O12-xBaTi O3(BIT-BT)压电陶瓷材料,研究了BaTi O3含量对BIT-BT陶瓷显微组织结构及电性能的影响规律。结果表明,BIT-BT陶瓷主要由Bi Ti3O12和BaTi O3两相组成,当0.1≤x(BT)≤0.7时,材料中出现BaBi4Ti4O1... 采用固相合成法制备了(1-x)Bi4Ti3O12-xBaTi O3(BIT-BT)压电陶瓷材料,研究了BaTi O3含量对BIT-BT陶瓷显微组织结构及电性能的影响规律。结果表明,BIT-BT陶瓷主要由Bi Ti3O12和BaTi O3两相组成,当0.1≤x(BT)≤0.7时,材料中出现BaBi4Ti4O15相。随着BT摩尔分数的增加,居里温度TC逐渐降低,介电常数εr逐渐增大,介电损耗tanδ和压电常数d33先增大后减小。当材料组分为0.6BIT-0.4BT时性能达到最佳,其TC=455℃、εr=147、tanδ=0.011、d33=20 pC/N。 展开更多
关键词 (1-x)bi4Ti3O12-xBaTiO3(biT-BT) 高居里温度 相结构 电性能
下载PDF
Ca^(2+)含量对(Na_(0.5)Bi_(0.5))_(1-x)Ca_xBi_4Ti_4O_(15)层状压电陶瓷的居里温度和性能的影响 被引量:3
6
作者 吴键 刘云飞 +1 位作者 吕忆农 李鸿鹏 《南京工业大学学报(自然科学版)》 CAS 北大核心 2013年第2期69-73,共5页
采用传统固相法制备铋层状(Na0.5Bi0.5)1-xCaxBi4Ti4O15(NCBT)压电陶瓷,其中x=0.1、0.2、0.3和0.4。利用X线衍射仪(XRD)、扫描电子显微镜(SEM)、同步热分析仪(STA)、阻抗分析仪等对陶瓷的结构和性能进行表征,分析不同Ca2+含量对NCBT压... 采用传统固相法制备铋层状(Na0.5Bi0.5)1-xCaxBi4Ti4O15(NCBT)压电陶瓷,其中x=0.1、0.2、0.3和0.4。利用X线衍射仪(XRD)、扫描电子显微镜(SEM)、同步热分析仪(STA)、阻抗分析仪等对陶瓷的结构和性能进行表征,分析不同Ca2+含量对NCBT压电陶瓷的居里温度和压电性能的影响。结果表明:在x=0.3条件下制备的NCBT陶瓷性能最佳,压电常数(d33)为17.7 pC/N,介电常数(εr)和介电损耗(tanδ)分别为163.8和0.28%(频率1 kHz),居里温度(Tc)为647.6℃。 展开更多
关键词 层状压电陶瓷 (Na0 5bi0 5)1-xCaxbi4Ti4O15 居里温度 介电性能 压电性能
下载PDF
Synthesis,Structural Characterization and Properties of Bis(1,5-diamino-1Htetrazolium)3,3'-bis(nitramino)-4,4'-azofurazan 被引量:3
7
作者 许诚 毕福强 +3 位作者 张敏 刘庆 丁可伟 葛忠学 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第9期1341-1346,共6页
An energetic salt of bis(l,5-diamino-lH-tetrazolium)3,3"-bis(nitramino)-4, 4x-azo- furazan (C6H10N2206) was synthesized with the total yield of 61.7% by using 3,4-diaminofurazan (DAF) as the starting material... An energetic salt of bis(l,5-diamino-lH-tetrazolium)3,3"-bis(nitramino)-4, 4x-azo- furazan (C6H10N2206) was synthesized with the total yield of 61.7% by using 3,4-diaminofurazan (DAF) as the starting material. The structure of the title compound was confirmed by NMR, IR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group P21/c with a = 10.739(2), b = 6.4765(12), c = 14.138(3) A, fl= 108.787(3)°, V= 930.9(3) A3, Z = 1, Mr= 486.36, Dc = 1.735 g.cm3, μ= 0.15 mm-1, F(000) = 496, R = 0.042 and wR = 0.121. The thermal stability was analyzed by subsequently differential scanning calorimetry (DSC). And the enthalpy of formation and detonation was calculated theoretically, showing the first decomposition temperature was 142.1℃, the enthalpy of formation was 1614.23 kJ.mol1 and the detonation velocity and detonation pressure were 8.781 km.s-1 and 30.7 GPa, respectively. 展开更多
关键词 bis(1 5-diamino-1H-tetrazolium)3 3?-bis(nitramino)-4 4?-azofurazan SYNTHESIS crystal structure furazan derivate
下载PDF
A Three-dimensional Porous Metal-organic Framework Based on Cyano Unit and 1,4-Bis(1,2,4-triazol-1-yl)butane(btb):{[Cu_8(btb)_2(CN)_8].3H_2O}_n 被引量:3
8
作者 周馨慧 李洪辉 黄维 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第1期33-38,共6页
The title coordination polymer 1,{[Cu8(btb)2(CN)8].3H2O}n(btb = 1,4-bis(1,2,4-triazol-1-yl)butane),has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction.Complex... The title coordination polymer 1,{[Cu8(btb)2(CN)8].3H2O}n(btb = 1,4-bis(1,2,4-triazol-1-yl)butane),has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction.Complex 1 crystallizes in monoclinic,space group C2/c with a = 1.2938(3),b = 1.9422(5),c = 0.9406(2) nm,β = 121.891(4)°,V = 2.0066(9) nm3,C24H30Cu8N20O3,Mr = 1155.00,Dc = 1.912 g/cm3,μ(MoKα) = 4.209 mm?1,F(000) = 1140,GOF = 1.184,Z = 2,the final R = 0.0634 and wR = 0.1503 for I 2σ(I).In complex 1,one-dimensional CuCN zigzag chains are linked by triazolyl groups of btb ligands to form two-dimensional networks,which are further bridged by 1,4-butyl moieties of btb ligands to fabricate a three-dimensional order framework,in which one-dimensional ellipsoid-like channels are observed. 展开更多
关键词 CYANO 1 4-bis(1 2 4-triazol-1-yl)butane metal-organic framework(MOF) complex Cu+
下载PDF
Synthesis and Structural Characterization of 2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol 被引量:3
9
作者 毕福强 王伯周 +4 位作者 樊学忠 许诚 葛忠学 刘庆 张国防 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第3期415-419,共5页
2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol(C6H12N2O8) was synthesized by condensation,cyclization,oxidative dimerization and deketalization of nitromethane with a total yield of 42.4%.The structure of the t... 2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol(C6H12N2O8) was synthesized by condensation,cyclization,oxidative dimerization and deketalization of nitromethane with a total yield of 42.4%.The structure of the title compound was characterized by 1H NMR,13C NMR,FT-IR,elementary analysis,and X-ray single-crystal diffraction analysis,which reveals that the title compound crystallizes in triclinic,space group P with a = 0.6324(2),b = 0.6454(3),c = 0.7062(3) nm,α= 111.550(4),β= 95.505(4),γ= 113.395(4)°,V = 0.23595(16) nm3,Z = 1,Mr = 240.18,Dc = 1.690 g·cm-3,μ = 0.159 mm-1,F(000) = 126,R = 0.0304 and wR = 0.0907. 展开更多
关键词 2 3-bis(hydroxymethyl)-2 3-dinitro-1 4-butanediol SYNTHESIS characterization crystal structure
下载PDF
Use of Ultrasound and Microwave Irradiation for Clean and Efficient Synthesis of 3,3’-(Arylmethylene)bis (2-hydroxynaphthalene-1,4-dione) Derivatives 被引量:2
10
作者 Aldo S. de Oliveira Luana C. Llanes +2 位作者 Ricardo J. Nunes Rosendo A. Yunes Inês M. C. Brighente 《Green and Sustainable Chemistry》 2014年第4期177-184,共8页
Nine 3,3’-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) derivatives were synthesized through the reaction between 2-hydroxy-1,4-naphthalen-1,4-dione and different aromatic alde-hydes in water applying ultrasonic... Nine 3,3’-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) derivatives were synthesized through the reaction between 2-hydroxy-1,4-naphthalen-1,4-dione and different aromatic alde-hydes in water applying ultrasonic irradiation for 5 min at room temperature and microwave irradiation for 15 min at 70°;C. Two of the nine derivatives, compounds 3-e and 3-i, obtained from 3-bromo-hydroxybenzaldehyde and 5-methylfuran-2-carbaldehyde, respectively, are previously unpublished. The structures of all compounds were established on the basis of their spectral data and mass analysis. The attractive features of this synthesis protocol include mild conditions, high atom-economy and excellent yields with the elimination of water as the only by-product. 展开更多
关键词 2-Hydroxy-1 4-naphthoquinone 3 3’-(Arylmethylene)bis(2-hydroxynaphthalene-1 4-dione) DERIVATIVES Green Chemistry
下载PDF
Preparation and Characterization of Bi_4Ti_3O_(12) Platelets by a Novel Low-temperature Molten Salt System 被引量:1
11
作者 隋万美 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第2期241-244,共4页
Bismuth titanate (Bi4Ti3O12) platelets were prepared by molten salt method in a new salt system of CaCl2·NaCl at 650-750℃, using bismuth nitrate pentahydrate (Bi (NO3)3·H2O) and titanium butoxide (Ti... Bismuth titanate (Bi4Ti3O12) platelets were prepared by molten salt method in a new salt system of CaCl2·NaCl at 650-750℃, using bismuth nitrate pentahydrate (Bi (NO3)3·H2O) and titanium butoxide (Ti (OC4H9)4) as raw materials. The synthesis temperature of Bi4Ti3O12 platelets was decreased to 650℃ from 900-1100℃. The phase compositions and crystalline morphology of Bi4Ti3O12 platelets were investigated by XRD and SEM. The experimental results indicate that Bi4Ti3O12 platelets containing tetragonal and orthorhombic phase with the size of 1-3μm can be synthesized at 650℃ for 2 h, and the orthorhombic phase becomes the dominant phase at 750℃ for 5 h. The size and proportion of Bi4Ti3O12 platelets increase with the increment of the calcining temperature and holding time. The proportion of platelets increases to about ninety percent, and the platelets grow up to about 3-10μm at 750℃ for 5 h from 1-2μm at 650℃ for 2 h. This technical route provides a new low-temperature molten salt system for preparing platelets by molten salt methods. 展开更多
关键词 CaCl2-NaC1 molten salt bi4Ti3O12 platelets
下载PDF
Syntheses, Structures and Characteristics of Two New Cu(II) Coordination Polymers Based on 4-tert-butyl-phthalate and Different Bis(1,2,4-triazol-1-yl) Co-Ligands 被引量:3
12
作者 韩民乐 凌勋利 +2 位作者 常新红 刘广臻 杜德光 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第4期543-550,共8页
Two new Cu(Ⅱ) coordination polymers, [Cu2(tbph)2(btb)2]n (1) and {[Cu2(tbph)2- (bth)2]·H2O}n (2), (H2tbph = 4-tert-butyl-phthalic acid, btb = 1,4-bis(1,2,4-triazol-1- yl)butane, bth = 1,6-bis(1... Two new Cu(Ⅱ) coordination polymers, [Cu2(tbph)2(btb)2]n (1) and {[Cu2(tbph)2- (bth)2]·H2O}n (2), (H2tbph = 4-tert-butyl-phthalic acid, btb = 1,4-bis(1,2,4-triazol-1- yl)butane, bth = 1,6-bis(1,2,4-triazol-l-yl)hexane), have been synthesized and characterized by elemental analysis, FT-IR and X-ray single-crystal diffraction. Complex 1 has a 2D sql layer. Complex 2 shows a (3,4)-connected 2D sheet with a (4.6^4.8)(4.8^2) topology. The thermal behavior of the two cor- responding complexes has briefly been investigated. 展开更多
关键词 Cu(Ⅱ) complex crystal structure 4-tert-butyl-phthalic acid 1 4-bis(1 2 4-triazol- 1-yl)butane 1 6-bis(1 2 4-triazol-1-yl)hexane
下载PDF
Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride 被引量:1
13
作者 Khodabakhsh Niknam Alireza Hasaninejad Madihe Arman 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第4期399-402,共4页
Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as ... Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions. 展开更多
关键词 Silica-supported tin chloride Silica-supported titanium tetrachloride bis-3 4-dihydropyrimidin-2(1H)-one SOLVENT-FREE 1 3-Dicarbonyl compounds
下载PDF
Weak Interactions and 2D Layer Structure of a New Ion-pair Complex Bis(1-benzyl-4-methylquinolinium)-bis(maleonitriledithiolato)nickel(Ⅱ)
14
作者 周家容 倪春林 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第11期1263-1266,共4页
A new ion-pair complex, [BzMeQ1]2[Ni(nmt)2]1([BzMeQ1]^+ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate) has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction ... A new ion-pair complex, [BzMeQ1]2[Ni(nmt)2]1([BzMeQ1]^+ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate) has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction methods. Complex 1 is of triclinic, space group PI, with a = 9.079(2), b = 10.154(2), c = 11.243(2)A, α= 81.58(1), β= 69.63(1), γ = 68.02(1)°, V= 940.1(3)A3, Dc = 1.427 g/cm^3, Z = 1, F(000) = 418 and R = 0.0442. A 2D layer structure is formed via the cation-cation π…π and C-H…π interactions observed in the solid state of the complex. 展开更多
关键词 1-benzyl-4-methylquinolinium bis (maleonitriledithiolate)nickclatc(Ⅱ) complex weak interactions 2D layer structure
下载PDF
Synthesis and Crystal Structure of 4,4'-(4-(1-Naphthyl)-4-phenyl-1,3-butadienylidene)-bis[N,N-diethylbenzenamine]
15
作者 LI Xiang-Gao WUAn-Shu XU De-Shun WANG Shi-Rong ZHAO Xue-Ming 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第9期1063-1066,共4页
The title compound (C40H42N2) has been synthesized by the reaction of l-(l- naphthyl)-l-phenyl-3-chloropropylene and bis(4-(diethylamino) phenyl)methanone, and characterized by IR, ^1H NMR, MS and X-ray diffra... The title compound (C40H42N2) has been synthesized by the reaction of l-(l- naphthyl)-l-phenyl-3-chloropropylene and bis(4-(diethylamino) phenyl)methanone, and characterized by IR, ^1H NMR, MS and X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 17.047(3), b = 10.807(2), c = 18.494(4) A, β = 105.727(4)°, V= 3279.4(11) A^3, Mr = 550.76, Z = 4, Dc = 1.115 g/cm^3,μ(MoKa) = 0.085 mm^-1, F(000) = 1184, the final R = 0.0625 and wR = 0.1384 for 2276 observed reflections (1 〉 2σ(I)). X-ray analysis reveals that the butadiene fragment adopts a planar cisiod conformation and makes a dihedral angel of 69.4(2)° with the naphthalene ring. 展开更多
关键词 4 4′-(4-(1-naphthyl)-4-phenyl-1 3-hutadienylidene)bis[N N-diethyl-benzenamine] synthesis crystal structure
下载PDF
输运溶剂浮区法生长Bi_(2+x)Sr_(2-x)Ca_(n-1)Cu_nO_(2n+4+d)晶体
16
作者 C.T.Lin(Max Planck Institute for Solid State Physics 70569 Stuttgart,Germany) 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期127-127,共1页
The growth of crystals of the high T c oxide superconductors has been hampe red by the complexities of the materials and their phase diagrams.The most common crys tal growth technique adopted for these oxides is the ... The growth of crystals of the high T c oxide superconductors has been hampe red by the complexities of the materials and their phase diagrams.The most common crys tal growth technique adopted for these oxides is the “flux”method,where the st arting materials are solved in a melt,which is usually formed by excess CuO and BaO or a KCl/NaCl mixture.The crystals are produced by slow cooling of the heate d solvent.This method,however,suffers from several disadvantages: (1) the crystals are contaminated with the crucible material, (2) the crystals are difficult to remove from the crucible, (3) the crystals contain flux inclusions. 展开更多
关键词 bi 2+ x Sr 2- x Ca n -1 Cu n O 2 n+4+d crystal travelling solvent floating zone method superconductor
下载PDF
Synthesis and Crystal Structure of 1,4-Bis-(benztriazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene
17
作者 CAI Yue-Peng HE Guang-Ping +3 位作者 CAI Yi ZHANG Chi SU Cheng-Yong KANG Bei-Sheng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第3期279-282,共4页
The title compound 1,4-bis(benztriazol-1-ylmethyl)-2,4,5,6-trimethylbenzene crys- tallizes in the monoclinic system, space group Pbca with a = 9.842(5), b = 9.455(5), c = 22.165(12) ?, V = 2062.6(18) ?3, Dc = 1.277 ... The title compound 1,4-bis(benztriazol-1-ylmethyl)-2,4,5,6-trimethylbenzene crys- tallizes in the monoclinic system, space group Pbca with a = 9.842(5), b = 9.455(5), c = 22.165(12) ?, V = 2062.6(18) ?3, Dc = 1.277 g/cm3, Z = 4, C24H24N6, Mr = 396.49, μ(MoKa) = 0.079 mm-1 and F(000) = 840. The structure was refined to R = 0.0662 and wR = 0.1891 for 1163 observed reflections (I > 2σ(I)). The title molecule has trans-conformation about the central phenyl ring. The zigzag-like molecules are connected by face-to-face π…π stacking to form an infinite 2D layer. 展开更多
关键词 bis(benztriazol-1-ylmethyl)-2 4 5 6-trimethylbenzene synthesis crystal structure face-to-faceπ…πinteraction 2D layer
下载PDF
Phase Transfer Catalyzed Synthesis of 1, 2-Bis[(3-aryl)-s-triazolo-[3, 4-b]-[1, 3, 4]thiadiazole-6-yl]ethanes
18
作者 De Jiang LI He Qing FU 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第6期755-756,共2页
A series of new 1, 2-bis[(3-aryl)-s-triazolo[3, 4-b]-[1, 3, 4]thiadiazole-6-yl]ethanes were synthesized in 50-82% yield by cyclization of 3-aryl-4-amino-5-mercapto-1, 2, 4-triazole with butanedioic acid in the prese... A series of new 1, 2-bis[(3-aryl)-s-triazolo[3, 4-b]-[1, 3, 4]thiadiazole-6-yl]ethanes were synthesized in 50-82% yield by cyclization of 3-aryl-4-amino-5-mercapto-1, 2, 4-triazole with butanedioic acid in the presence of POC13 and tetrabutylammonium iodide as phase transfer catalyst. 展开更多
关键词 1 2 4-Triazoles bis-triazolothiadiazoles synthesis.
下载PDF
Synthesis and Characterization of a Novel Copoly(aryl ether ketone) Containing 4, 4'-Biphenyl-bis[4-phthalazin-1(2H)-one] Moiety
19
作者 Shao Yin ZHANG Xi Gao JIAN +2 位作者 Shu De XIAO Jin Yan WANG Jie ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第2期145-146,共2页
A new monomer of 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA... A new monomer of 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA), 4, 4'-biphenyl-bis-[4-phthalazin-1(2H)-one], 4, 4- difluorodiphenylketone (DFK). The monomer and copolymer were characterized by FT-IR and 1H-NMR. DSC and TGA were used to the novel polymer. 展开更多
关键词 Poly(aryl ether ketone) 4 4'-biphenyl-bis[4-phthalazin-1(2H)-one] 2 2-bis(4-hydroxy- phenyl)-propane(BPA).
下载PDF
Synthesis, Reactions and Characterization of 1,1’-(1,4-Phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(ethan-1-one)
20
作者 Ahmed A. M. Elreedy Hameed M. Alkubaisi Fawzy A. Attaby 《International Journal of Organic Chemistry》 CAS 2016年第1期65-76,共12页
Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). Th... Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses. 展开更多
关键词 bis-1 2-dihydropyridine-3-carbonitrile bis-Nicotinonitrile 1 1’-(1 4-Phenyl-enebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3 4-b]pyri-dine-4 5-diyl))bis(ethan-1-one) bis-dihydropyrido[2’ 3’:3 4]pyrazolo[5 1-c][1 2 4]triazine-3-carboxylate bis-1H-pyrazolo[3 4-b]pyridine
下载PDF
上一页 1 2 15 下一页 到第
使用帮助 返回顶部