共查询到20条相似文献,搜索用时 15 毫秒
1.
XIA Xin 《高等学校化学研究》1994,(3)
KineticStudiesonAxialCoordinationReactionofTetraphenylporphinatocobalt(Ⅱ)ChlorideXIAXin(Dept.ofChem.,BeijuigSci&Tech,Univ.,Be... 相似文献
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选择一种金属卟啉有机物(5-对-烷氧基苯基-10,15,20-三苯基卟啉羟基稀土化合物, HoOH)和4,4'-联吡啶(44BPY)作为自组装膜的基本构筑单元, 利用金属配位作用, 成功地将HoOH单分子膜组装到44BPY修饰的银表面. 采用紫外-可见吸收光谱、表面增强拉曼光谱研究了金属卟啉自组装膜的形成并且探索其结构和取向的变化. 结果表明, 底层的44BPY通过4位的N原子垂直吸附到银表面, 另一端的吡啶环上的N原子与HoOH的金属中心配位形成化学键. 从而在44BPY长轴向方向上将HoOH连接到44BPY自组装膜上, 并形成了新的交替膜. 之后, 底层的44BPY取向发生变化, 更向基底倾斜, 而上层的HoOH的分子平面则近乎平行于基底. 相似文献
3.
Michael T.M. Choi 《Tetrahedron》2004,60(32):6889-6894
Bis(4-pyridinolato) silicon(IV) phthalocyanine (1) binds with a series of zinc(II) tetrapyrrole derivatives with the two pyridyl ligands forming the corresponding 1:2 or 1:1 molecular assemblies. The molecular structure of the first axially linked trinuclear phthalocyanine-porphyrin array has also been determined. 相似文献
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A general method that uses potassium organotrifluoroborates in the Suzuki-Miyaura cross-coupling reaction with ring-brominated porphyrins has been investigated. The reaction conditions tolerate various functional groups and are applicable to the meso- and β-position as well as to aryl- and alkyl-substituted porphyrins. Depending on the nature of the potassium organotrifluoroborate, the coupling products can be obtained in yields of up to 75%. 相似文献
6.
通过轴向配位反应,将四苯基卟啉锌(ZnTPP)键合在4-乙烯基吡啶(4VP)与苯乙烯(St)共聚物P(4VP-co-St)的侧链,制得了卟啉功能化的大分子ZnTPP-P(4VP-co-St).通过FTIR与1H-NMR对其化学结构进行了表征,重点研究了时间、温度对轴配过程的影响,以及大分子轴配化合物ZnTPP-P(4VP-co-St)的谱学性能,对其光物理行为进行了较为深入的分析.研究结果表明,以共聚物P(4VP-co-St)的吡啶侧基为配体,通过轴向配位反应可顺利地制备卟啉功能化的大分子ZnTPP-P(4VP-co-St),且温度越低,键合量越大.该大分子具有类似于ZnTPP的特征电子吸收光谱与荧光发射光谱,同时也显示出轴向配位的特征.与小分子ZnTPP相比,ZnTPP-P(4VP-co-St)的吸收光谱和发射光谱都发生了明显的红移.大分子轴配化合物ZnTPP-P(4VP-co-St)的光物理行为也呈现出一定程度的高分子效应,随着大分子链中ZnTPP键合量的增大,相近的ZnTPP侧链单元之间会发生能量转移,使荧光发射强度有所减弱. 相似文献
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The thermodynamics of axial coordination reactions of Fe-phthalocyanine with various ligands of imidazoles in DMF solution has been studied. The axial coordination number(n)and equilibrium constants (βn) of the coordinating reaction were determined by spectral techniques. The steric and electrionic effects of the axial ligands were compared. The influence of temperature on the coordination reactions was discussed. The difference of axial coordinations of metallo-phthalocyanine and metallo-porphyrin with imidazoles was also analyzed. 相似文献
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Knorr-type condensation of cyclododecanone, cyclopentadecanone, and cyclohexadecanone with phenylhydrazones derived from acetoacetate esters in the presence of zinc dust at elevated temperatures gave the corresponding large ring cycloalka[b]pyrroles in excellent yields. A cyclohexadeca[b]pyrrole was reacted with lead tetraacetate to give an acetate derivative, and this condensed with α-unsubstituted pyrroles in the presence of p-toluenesulfonic acid in acetic acid to give a series of related dipyrrolic structures. Hydrogenolysis of the benzyl ester protective groups, followed by ‘2+2’ condensations with dipyrrylmethane dialdehydes, gave unusual cycloalkanoporphyrins with 16-membered exocyclic rings. When an alkyl group is situated next to the carbocyclic ring, proton NMR spectroscopy indicates that the conformational mobility of the carbocyclic unit is severely restricted. 相似文献
9.
氨功能化介孔MCM-41固载锰卟啉作为萘羟基化多相催化剂 总被引:1,自引:0,他引:1
将不同含量的四(五氟苯基)卟啉锰固载于表面氨基功能化的MCM-41介孔分子筛,所得样品通过粉末X射线衍射、氮气吸附脱附、傅里叶变换红外光谱、X射线光电子能谱、扫描电子显微镜、漫反射紫外-可见光谱、热重和差示扫描量热、电感耦合等离子体进行了表征.结果表明,四(五氟苯基)卟啉锰通过Mn与氨基的轴向配位固载于MCM-41.所制备的样品作为多相催化剂在以间氯过氧苯甲酸为氧化剂选择氧化萘反应中表现出良好的催化性能,且多次使用后没有明显的活性损失. 相似文献
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We report the efficient synthesis of tetrabicycloporphyrin titanyl and vanadyl without decomposition of the bicyclo[2.2.2]octadiene unit. The complexes were heated under vacuum to give titanyl and vanadyl tetrabenzoporphyrins in 100% yield. We also titanylated and vanadylated tetra[2,3]naphthoporphyrin and tetra[2,3]anthraporphyrin, which have a greater degree of π conjugation than tetrabenzoporphyrin. 相似文献
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吡啶存在下(TPP)Co的电化学氧化还原行为研究 总被引:1,自引:0,他引:1
本文考究了吡啶对Co在1,2-二氧乙烷中的电化学氧化还原行的影响,观察到当存在一定量Py时,CO(Ⅲ)/Co(Ⅱ)还原过程出现两个还原峰,分别在0.25和-0.40V两处。 相似文献
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A systematic study for the effect of axially coordinated monovalent anions on the electrode reactions of several manganese porphyrins in acetonitrile is presented. Potential shifts of the metal-centered reduction with changes in counterion were related to the degree of Mn(III)-counterion interaction. In the electrochemically induced ligand exchange, perchlorate anion replaces the other anions as axial ligand coordinated to Mn(III) at oxidation potential less than the first oxidation of manganese porphyrins. Formation constants for axial ligation of OH? are calculated. One-electron oxidation of dihydroxide coordinated manganese porphyrins generate oxomanganese(IV) porphyrin complexes electrochemically. O=MnIVOEP(OH) is more thermodynamically stable than O=MnIVTPP(OH), while O=MnIVTpFPP(OH) cannot be generated electrochemically. In the presence of styrene or cyclohexene, the absorption spectra of oxomanganese(IV) porphyrins are changed to form manganese(III) porphyrins gradually, which indicates the oxygen atom transfer from oxomanganese(IV) porphyrins to the substrates. 相似文献
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锌卟啉配合物轴配反应的光谱及电子效应 总被引:1,自引:0,他引:1
用紫外-可见分光光度计研究了三种新型空间不对称金属席夫碱和四种取代咪唑与间位取代四苯基卟啉锌(ZnT(m-X)PP,X=NO2,Cl,OCH3,H,CH3)在CH2Cl2中的轴向配位反应的紫外-可见吸收光谱,发现在450-700nm间存在等吸光点;采用Rose-Drago数据处理方法确定了各体系在25℃时平衡常数,发现所研究的35个配位反应体系的配位数均为1,各配体与锌卟啉配位反应的εβ/εα及平衡常数均分别与卟啉环上取代基的Hammett参数间存在线性自由能关系. 相似文献
15.
A thermodynamic study is reported for the coordination reaction of ZnT ( m-X)PP derivatives (X = NO2, Cl, OCH3, H or CH3) with various ligands L (L= imidazole (Im), 2-methylimidazole (MeIm), clotrimidazole (CIM), imidazole-4-carboxaldehyde (4-CHOIm), unsymmetrical tetradentate copper Schiff base, CuIm(p-Cl), CuIm(p-Br), and nickel Schiff base, NiIm(p-Cl)), in dichloromethane solvent. Conversion of the four-coordinated ZnT( m-X)PP to the five-coordinated species is followed and isosbestic behavior is exhibited in the region among 450 and 700 run. The reaction of a copper(Ⅱ) or nickel(Ⅱ) imidazolate Schiff base with ZnT(m-X)PP results in the formation of an imidazolate bridged heterobinuclear complex. The stoichiometric number is unity for all axial ligands. The equilibrium constants were determined using the β band of ZnT( m-X)-PP in the 293-308 K range by the method of Rose and Drago. It increases with decrease in temperature, and △H0 < 0, △S0 < 0. The stronger the nucleophilic ability of the axial 相似文献
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Abhijeet Singh Jagmeet Singh Prof. Dr. Mahendra Nath 《European journal of organic chemistry》2023,26(4):e202201319
A facile synthetic strategy for the synthesis of a new series of β,β’-fused 2-arylpyrimido[4,5-b]porphyrins has been developed by using condensation cyclization reaction with ammonia. 2-Aroylamino-3-formylporphyrins were synthesized from 2-aroylaminoporphyrins under Vilsmeier–Haack reaction conditions, which were then efficiently converted to the corresponding 2-arylpyrimido[4,5-b]-5,10,15,20-tetrakis(4-chlorophenyl)-porphyrins via a condensation cyclization reaction. The nickel(II), copper(II), free-base and zinc(II) analogues of 2-arylpyrimido[4,5-b]porphyrins were successfully synthesized in 65–72 % yields and structurally characterized on the basis of spectral data analysis. On photophysical evaluation, 2-arylpyrimido[4,5-b]porphyrins demonstrated a 12–19 nm bathochromic shift in their electronic absorption spectra and up to 10 nm red shift in their emission spectra as compared to the simple meso-(tetrakis(4-chlorophenyl))porphyrins due to the extended π-conjugation. 相似文献
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F-的轴向配位对(TPP)Co电化学氧化还原的影响研究 总被引:2,自引:0,他引:2
钻卟啉的电化学氧化还原行为受轴向配位作用的影响很大[1-5]。通过循环伏安跟踪的阴离子滴定可以细致地考察此影响过程,但至今很少见文献报道[4,5].我们曾研究了Br-和Cl-存在时,(TPP)Co的电化学氧化行为特征,结果显示不同的卤离子对(TPP)Co电化学氧化还原过程的影响程度有相当大的差别[6,7].本文以循环伏安跟踪的F-滴定和光谱电化学方法研究了F-的轴向配位效应对(TPP)Co在1,2一二氯乙烷中电化学氧化还原过程的影响.1试剂与仪器1,2一二氯乙烷(DCE,北京化工厂,分析纯),在CaH。上分馏纯化后使用,四丁基高… 相似文献
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用超导核磁共振研究了4种咪唑配体与金属卟啉铁(Ⅲ)和锰(Ⅲ)配位的交换反应动力学.探讨了不同轴向配体对同一金属卟啉、金属卟啉环上取代基、不同金属离子以及温度等因素对交换反应动力学的影响,进一步验证了线性热力学函数关系的存在. 相似文献
19.
For the widely studied high-carrier-mobility species, pentacene, it is found that perfluorination turned it into an n-type organic field-effect transistor (OFET), but doubled the internal reorganization energy (lambda) of the electron/hole hopping. Here, Cl- and N-functionalized pentacenes are designed to test two strategies that may reduce the impact of functionalization on lambda. Calculation results show that the strategies are feasible. Moreover, combined with crystal-structure data of Cl- and N-functionalized aromatic compounds, it is concluded that compared to fluorination, the presence of Cl and N atoms in pentacene not only reduces the influence of functionalization on lambda and affords a larger window for tuning HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energies, but also provides the opportunity to promote pi-stacked structures through ClCl and C--HN interactions. 相似文献
20.
Mohammed Krouit 《European Polymer Journal》2009,45(4):1250-3539
Two series of porphyrinic cellulose laurate esters plastic films, where the photosensitizers are covalently linked to the cellulosic polymer have been synthesised by using a “one-pot, two-step” esterification reaction. The photosensitizers were first covalently bounded to the cellulosic polymer using either 4- or 11-carbon spacer arms. The porphyrinic plastic films were then obtained by a second esterification with lauric acid. The reaction was studied according to reaction time, temperature, lauric acid amount, pyridine playing the role proton trapping base. Para-toluenesulfonylchloride has been proved to be a powerful activating agent for this reaction. The drawback of the steric hindrance of the porphyrinic macrocycle towards cellulosic hydroxyl groups has been overcome by increasing the number of carbon of spacer arms from 4- to 11-carbons. The photobactericidal activity of these materials was evaluated against Gram positive and Gram negative strains bacteria. First results show that these new plastic films display photobactericidal activity for porphyrin grafting percentage higher than 0.16, whereas the non-porphyrinic control allowed full growth of bacteria. These materials could be an alternative in order to overcome the growing bacterial multiresistance to classical antibiotics. 相似文献