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1.
四苯基卟啉对二苯并咪唑光电导性能的敏化 总被引:6,自引:0,他引:6
采用溶剂球磨分散法制备了四苯基卟啉(H2TPP)/二苯并咪唑(Im-PTC)复合光生材料,用浸涂法将其制成功能分离型双层光导体.采用光致释电法对其光电导性能进行测试,发现在500nm下,由质量分数5%H2TPP/40%Im-PTC复合光生材料制备的光导体的光敏性比单纯40%的Im-PTC制备的光导体提高了3.5倍,说明H2TPP对Im-PTC有明显的敏化作用.进一步研究了该复合材料的电子结构,结果表明,H2TPP与Im-PTC存在分子间的光致电荷转移,从而提高了电荷的光生和分离效率,增强了光导体的光敏性. 相似文献
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采用以溶剂热方法合成的CdS纳米棒与酞菁氧钛复合制备的复合光导体,在570nm光照下其光电导性能明显提高,将质量分数为5%的CdS纳米棒与TiOPc复合使光敏性能提高32%.电子结构的数据和表面光电压谱分析结果表明,复合体系中存在从CdS纳米棒到TiOPc的光致空穴转移,TiOPc因被CdS纳米棒敏化而表现出高的光电导性能. 相似文献
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自从60年前[1]金属酞菁被发现以来,就引起人们的广泛兴趣,其原因主要在于它们在染料颜料、光化学、催化、和成像中的应用. 和许多其它酞菁衍生物一样,钒氧酞菁具有光导和半导体特性,这使得它在光电子学、电子成像、化学传感器、甚至于微电子器件中有潜在的十分光明的应用前景[2]. 例如, 钒氧酞菁在电子成像体系中已成为有用的感光材料. 近年来,金属酞菁等有机材料的结晶薄膜开始不断地吸引人们的注意力. 人们考察了不同的金属酞菁如: 酞菁铜、酞菁铅、酞菁镍、和酞菁锡 等的光电导和光电压[3]. 通常酞菁以几种不同的多晶异构体、即以不同的晶体排列结构方式存在. 因此,其光电特性不仅取决于分子中心的金属原子、而且取决于它们的晶体结构. 总之,值得我们研究钒氧酞菁薄膜的光电特性以及它与吸收光谱和薄膜晶体结构的关系. 相似文献
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本文主要介绍了醛类共还原体系和卟啉类、酞菁类、席夫碱类过渡金属仿生催化体系对分子氧的活化机理及在烯烃环氧化中的应用研究。醛类共还原体系的活性中心为过氧自由基,而卟啉类、酞菁类、席夫碱类过渡金属仿生催化剂与分子氧络合后将配位双氧变为超氧型或过氧型,酞菁还可作为光敏剂,在可见光激发下,与氧气分子发生能量转移,产生单线态氧。 相似文献
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以不同方法制备了两种不同晶型的酞菁氧钒(VOPc),X-射线分析结果表明,一为多晶型,另一种为非晶型。两种晶型在红外区都具有光导性,非晶型的光导性更好。 相似文献
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比较了几种金属酞菁光敏产生单重态氧和超氧负离子的能力,结果表明它们产生1O2的能力与中心金属的电子结构有关,取决于三重态寿命和量子产率。顺序如下:Zn>Ga>Cu>H2>Al>Co。产生O2·-的能力不仅与三重态寿命和量子产率有关,也与激发能和氧化还原电位有关。其顺序如下:Ga>Al>Cu>Zn。还研究了酪氨酸与镓酞菁激发态相互作用,酪氨酸猝灭镓酞菁荧光。在除氧条件光激发下,酪氨酸猝灭镓酞菁的激发三重态发生电子转移,检测到GaTSPc-在560nm处的瞬态吸收,在氧的存在下进一步反应生成O2·-。 相似文献
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本文分别用1064nm, 532nm和 355nm激发波长的YAG脉冲激光对所制备的phase Ⅱ结构钒氧酞菁膜Al\phase ⅡVOPc\ITO夹心电池进行瞬态光电压响应研究.随着3种波长激发光脉冲强度的增加, 瞬态光电压信号均增强. 激发光波长1064nm、532nm处于酞菁膜Q-带吸收区肩部, 光电压的极性与激发光入射方向无关, 均为负信号; 而激发光波长 355nm处于酞菁膜B-带, 光电压的极性与激发光入射方向有关, 从ITO极方向激发产生正电压信号, 从A1极激发产生负电压信号. 激发光波长对夹心电池的光电压产生有明显的作用, 光电压产生过程中应存在不同的机理. 这与前文[1]对同一夹心电池稳态光电压响应研究所推断的结论一致. 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献