层状嵌接式酞菁材料对烷烃的非均相氧化催化作用

层状嵌接式酞菁材料对烷烃的非均相氧化催化作用胡希明皮宗新古国榜黄仲涛＋（华南理工大学应用化学系化学工程系＋广州５１０６４１）关键词嵌接式酞菁层状锑磷酸Ｈ２Ｏ２氧化催化酞菁是一种金属离子被吡咯环包围的“镶木工艺品式”平面网络状配位化合物。在结构上它与叶...     

Triton X－100／C_（10）H_（21）OH／H_2O体系层状液晶中水溶性超微粒子材料Na_2C_2O_4的制备

利用溶剂在层状液晶中的渗透性和层状液晶中溶剂层厚度的限定性，在ＴｒｉｔｏｎＸ－１００／Ｃ_（１０）Ｈ_（２１）ＯＨ／Ｈ_２Ｏ体系层状液晶中，以饱和Ｎａ_２Ｃ_２Ｏ_４水溶液代替组分水制备水溶性超微粒子材料Ｎａ_２Ｃ_２Ｏ_４，平均粒径约为６ｎｍ．     

Triton X—100／C10H21OH／H2O体系层状液晶中水溶性超微粒子材…

利用溶剂在层状液晶中的渗透性和层状液晶中溶剂层厚度的限定性，在ＴｒｉｔｏｎＸ－１００／Ｃ１０Ｈ２１ＯＨ／Ｈ２Ｏ体系状液晶中，以饱和Ｎａ２Ｃ２Ｏ４水溶液代替给分水制备水溶性超微粒子材料Ｎａ２Ｃ２Ｏ４，平均粒径约为６ｎｍ。     

层状锑磷酸嵌接式卟啉锰制备与模拟细胞色素氧化催化研究

层状锑磷酸嵌接式卟啉锰制备与模拟细胞色素氧化催化研究胡希明，皮宗新，梅治乾，古国榜，黄仲涛（华南理工大学应用化学系，华南理工大学化学工程系，广州，５１０６４１）关键词卟啉锰，层状锑磷酸，嵌接，催化性能细胞色素Ｐ４５０是一种含血红素的单充氧化酶，在室温...     

Triton X－100／C_（10）H_（21）OH／H_2O体系层状液晶中超微粒子材料CdS的合成

ＴｒｉｔｏｎＸ－１００／Ｃ_（１０）Ｈ_（２１）ＯＨ／Ｈ_２Ｏ体系层状液晶中超微粒子材料ＣｄＳ的合成沈明，郭荣，严鹏权，于卫里（扬州大学师范学院化学系扬州２２５００２）关键词超微粒子，层状液晶，表面活性剂，ＴｒｉｔｏｎＸ－１００，ＣｄＳ超微粒子是指粒径?..     

一硝基四苯基卟啉及其Cu(Ⅱ)、Zn(Ⅱ)配合物的电化学和光谱电化学

以卟啉环为配体的金属卟啉配合物具有特殊的光、电、磁及生物功能．在卟啉骨架的吡咯环上引入拉电子基团如ＣＮ或Ｂｒ等,能改变卟啉的氧化还原电位;当有ＰｈＩＯ、Ｈ２Ｏ２、ＮａＯＣｌ、ＲＣＯ３Ｈ等氧化剂存在时,这类卟啉衍生物可作为有机环氧化的催化剂．因此对环取...     

维生素C在CTAB／n—C5H11OH／H2O体系中的增稳作用

在ＣＴＡＢ／ｎ－Ｃ５Ｈ１１ＯＨ／Ｈ２Ｏ体系中，维生素Ｃ存在于Ｏ／Ｗ、Ｗ／Ｏ液滴的内侧，Ｃ５Ｈ１１ＯＨ则存在于液滴的外侧，阻碍渗透进入膜相中的水与维生素Ｃ的接触，从而在幅芳降低了维生素Ｃ在水体系中的氧化程度，提高了其稳定性，Ｏ／Ｗ、Ｗ／Ｏ微乳液对维生素Ｃ分子艇的机理亦从层状液晶对其增稳作用中得到证明。     

金属卟啉－甲基紫精二连体配合物的合成及其光化学行为

本文合成了四（对－氯代甲基）苯基－甲基紫精卟啉及其Ｚｎ、Ｃｏ、Ｍｎ配合物，用元素分析、红外光谱和紫外可见光谱进行了表征．研究了它们的光化学性质．结果表明．在ＴＥＯＡ中光照使Ｍ·ＴＣＭＰＰ—ｍｖ￣２＋发生了分子内从卟啉到甲基紫精的电子迁移反应．在ＺｎＴＣＭＰＰ－ｍｖ￣２＋／ＴＥＯＡ／ＤＭＳＯ—Ｈ２Ｏ体系中可发生光敏化还原ｍｖ２＋反应，生成较稳定的ｍｖ＋．在Ｍｎ（Ⅲ）ＴＣＭＰＰ－ｍｖ２＋／ＣＨ３ＯＨ／Ｈ２Ｏ体系中可发生光助氧化甲醇反应，并检出了氧化产物甲醛．     

双金属复合氧化物的结构与紫外阻隔性能

双金属复合氧化物（ＣＬＤＨ）是一类发展迅速的无机层状材料的煅烧产物,在催化、吸附等领域已获长足进展［１］,但作为紫外阻隔材料的性能研究尚鲜见报道．本文研究了不同双金属复合氧化物的紫外阻隔性能,结果发现二价金属离子为锌离子的ＣＬＤＨ具有良好的紫外阻隔性能．实验所用试剂均为分析纯．ＣＬＤＨ由ＮａＯＨ,Ｎａ２ＣＯ３,ＭｇＳＯ４·７Ｈ２Ｏ,ＺｎＳＯ４·７Ｈ２Ｏ,Ａｌ２（ＳＯ４）３·１８Ｈ２Ｏ为原料,按文献［２］方法制备．ＺｎＯ＋Ａｌ２Ｏ３复配物是按一定比例机械混合后,研磨,并在与ＣＬＤＨ相同的条件下煅烧…     

α-磷酸锆层柱材料的制备、表征及其催化羰基化性能

采用配体４－ＣＨ３ＳＣ６Ｈ４ＮＨ２插层的α－磷酸锆为插层主体,将Ｒｈ６３＋引入层状材料的层析之间制备了新型层柱催化材料Ｚｒ（ＨＰＯ４）１．７０（ＣＨ３ＳＣ６Ｈ４ＮＨ２）１．０９（ＰＯ４）０．３０Ｒｈ０．１０．５．５２Ｈ２Ｏ,其是距为２．３６变为１．５６ｎｍ,结晶度有所下降。     

固载化阳离子金属卟啉/杂多阴离子复合催化剂在分子氧氧化乙苯过程中的催化特性

以交联聚苯乙烯微球(CPS)为基质载体, 采用同步合成与固载的方法, 简捷地制得了固载化阳离子苯基卟啉, 继而通过与钴盐的配合反应, 制备了固载化阳离子钴卟啉. 在此基础上, 以Keggin 型杂多酸磷钨酸(HPW)及磷钼酸(HPMo)为试剂, 凭借阳离子钴卟啉(CoP)与杂多阴离子之间的静电相互作用, 制备与表征了固载化的由阳离子钴卟啉与杂多阴离子复合而成的固体催化剂CoPPW-CPS和CoPPMo-CPS. 将两种复合催化剂用于分子氧氧化乙苯的氧化反应, 考察研究了催化特性. 结果表明: 在分子氧氧化乙苯的氧化反应中, 复合催化剂具有很高的催化活性, 可使乙苯高选择性地转化为苯乙酮, 反应12 h, 苯乙酮的产率达30.1%; 复合催化剂的催化活性比单纯的固载化钴卟啉高75%; CoPPW-CPS的催化活性高于CoPPMo-CPS. 在复合催化剂结构组分中, 固载化的杂多阴离子并无催化活性, 起催化作用的组分是钴卟啉; 但是, 杂多阴离子可有效保护钴卟啉, 使其免于被氧化失活, 从而使其保持稳定的高催化活性. 复合催化剂具有最适宜的投加量, 过量催化剂的加入, 会抑制钴卟啉的催化活性. 复合催化剂还具有良好的循环使用性能.     

Electrochemical reduction of carbon dioxide catalyzed by cofacial dinuclear metalloporphyrin

Cofacial dinuclear metalloporphyrins exhibited a catalytic activity for the electrochemical reduction of carbon dioxide. The cofacial dinuclear porphyrin was automatically generated by mixing a cationic cobalt porphyrin (CoTMPyP) and an anionic metalloporphyrin (MTPPS) in solution. The redox system of this complex was examined by electrochemical methods. According to the cyclic voltammogram, the catalytic active species was generated at −1.8V vs. Ag/Ag⁺, which was considered to be a monovalent cobalt porphyrin, Co(I)TMPyP. The catalytic activity of the dinuclear complex was two times greater than that of the mononuclear one because the anionic porphyrin acted as an electron mediator.     

Self-assembled molecular rafts at liquid|liquid interfaces for four-electron oxygen reduction

The self-assembly of the oppositely charged water-soluble porphyrins, cobalt tetramethylpyridinium porphyrin (CoTMPyP(4+)) and cobalt tetrasulphonatophenyl porphyrin (CoTPPS(4-)), at the interface with an organic solvent to form molecular "rafts", provides an excellent catalyst to perform the interfacial four-electron reduction of oxygen by lipophilic electron donors such as tetrathiafulvalene (TTF). The catalytic activity and selectivity of the self-assembled catalyst toward the four-electron pathway was found to be as good as that of the Pacman type cofacial cobalt porphyrins. The assembly has been characterized by UV-visible spectroscopy, Surface Second Harmonic Generation, and Scanning Electron Microscopy. Density functional theory calculations confirm the possibility of formation of the catalytic CoTMPyP(4+)/ CoTPPS(4-) complex and its capability to bind oxygen.     

Catalytic hydrodebromination of aryl bromides by cobalt tetra-butyl porphyrin complexes with EtOH

Hydrodebromination of aryl bromides catalyzed by electron rich and sterically unhindered cobalt 5,10,15,20-tetrabutylporphyrin was achieved at mild conditions in good yields employing EtOH as the hydrogen source. The catalytic efficiency was enhanced compared with previously reported by cobalt tetra-aryl porphyrin catalysts. A revised mechanism of single electron transfer was proposed.     

Concerning the Deactivation of Cobalt(III)‐Based Porphyrin and Salen Catalysts in Epoxide/CO2 Copolymerization

Functioning as active catalysts for propylene oxide (PO) and carbon dioxide copolymerization, cobalt(III)‐based salen and porphyrin complexes have drawn great attention owing to their readily modifiable nature and promising catalytic behavior, such as high selectivity for the copolymer formation and good regioselectivity with respect to the polymer microstructure. Both cobalt(III)–salen and porphyrin catalysts have been found to undergo reduction reactions to their corresponding catalytically inactive cobalt(II) species in the presence of propylene oxide, as evidenced by UV/Vis and NMR spectroscopies and X‐ray crystallography (for cobalt(II)–salen). Further investigations on a TPPCoCl (TPP=tetraphenylporphyrin) and NaOMe system reveal that such a catalyst reduction is attributed to the presence of alkoxide anions. Kinetic studies of the redox reaction of TPPCoCl with NaOMe suggests a pseudo‐first order in cobalt(III)–porphyrin. The addition of a co‐catalyst, namely bis(triphenylphosphine)iminium chloride (PPNCl), into the reaction system of cobalt(III)–salen/porphyrin and PO shows no direct stabilizing effect. However, the results of PO/CO₂ copolymerization by cobalt(III)–salen/porphyrin with PPNCl suggest a suppressed catalyst reduction. This phenomenon is explained by a rapid transformation of the alkoxide into the carbonate chain end in the course of the polymer formation, greatly shortening the lifetime of the autoreducible PO‐ring‐opening intermediates, cobalt(III)–salen/porphyrin alkoxides.     

Diastereoselective and enantioselective cyclopropanation of alkenes catalyzed by cobalt porphyrins

Cobalt(II) porphyrin complexes were shown to be general and efficient catalysts for selective cyclopropanation of alkenes with ethyl diazoacetate (EDA). The catalytic system can operate with alkenes as limiting reagents, requiring only stoichiometric amounts of EDA. The protocol is performed in one-pot fashion without the need of slow addition of EDA. The diastereoselectivity of the current system can be tuned by using different porphyrin ligands or additives, giving either trans- or cis-dominant cyclopropanes. The asymmetric cyclopropanation was also demonstrated with the use of chiral cobalt porphyrin complexes.     

Catalytic activity and stability of anionic and cationic water soluble cobalt(II) tetraarylporphyrin complexes in the oxidation of 2-mercaptoethanol by molecular oxygen

The catalytic activity and stability of anionic cobalt(II) porphyrin complexes: 5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphyrinatocobalt(II), 5,10,15,20-tetrakis(2,4,6-trimethyl-3,5disulfonatophenyl)porphyrinatocobalt(II) and the cationic cobalt(II) porphyrin: 5,10,15,20-tetrakis[4-(diethylmethylammonio)phenyl]porphyrinatocobalt(II) tertraiodide have been investigated in the oxidation of 2-mercaptoethanol by dioxygen. All complexes were efficient catalysts for the auto-oxidation of 2-mercaptoethanol. The cationic cobalt(II) porphyrin has been found to be the most reactive catalyst. The rate of auto-oxidation of 2-mercaptoethanol catalysed by 5,10,15,20-tetrakis(2,4,6-trimethyl-3,5disulfonatophenyl)porphyrinatocobalt(II) has been found to increase with increasing the pH from 7 to 9 then decreased at higher pH. The rate constants of auto-oxidation reaction showed linear dependence on catalyst concentration and saturation kinetics in both 2-mercaptoethanol concentrations and dioxygen pressure. Anionic cobalt(II) porphyrin complexes showed higher stability than the cationic catalyst in repeat oxidation reactions. Immobilizing the anionic catalysts on ion exchange resin and supporting the cationic catalyst on clay mineral montmorillonite improved their stabilities towards oxidation.     

First insight into catalytic activity of anionic iron porphyrins immobilized on exfoliated layered double hydroxides

Mg-Al layered double hydroxide (LDH) intercalated with glycinate anions was synthesized through co-precipitation and exfoliated in formamide and the single-layer suspension was reacted with aqueous iron porphyrin solutions (Fe(TDFSPP) and Fe(TCFSPP)). The obtained materials were characterized by X-ray powder diffraction, UV-vis, and electron paramagnetic resonance and investigated in the oxidation reaction of cyclooctene and cyclohexane using iodosylbenzene as oxidant. The iron porphyrin seems to be immobilized at the surface of the glycinate intercalated LDH. The catalytic activities obtained in heterogeneous media for iron porphyrin, Fe(TDFSPP), was superior to the results obtained under homogeneous conditions, but the opposite effect was observed on the Fe(TCFSPP), indicating that, instead of the structural similarity of both iron porphyrins (second-generation porphyrins), the immobilization of each one produced different catalysts. The best catalytic activity of the Fe(TDFSPP)/Gly-LDH, compared to Fe(TCFSPP)/Gly-LDH, can be explained by the easy access of the oxidant and the substrate to the catalytic sites in the former, probably located at the surface of the layered double hydroxide pillared with glycinate anions. A model for the immobilization and a mechanism for the oxidation reaction will be discussed.     

Synergetic activation of carbon dioxide molecule using phenylazomethine dendrimers as a catalyst

Phenylazomethine dendrimers bearing a cobalt porphyrin core act as catalysts for CO₂ reduction in the presence of a strong Lewis acid such as lanthanide trifluoromethanesulfonate (Ln(OTf)₃). We investigated the catalytic activity using electrochemical measurements (cyclic voltammetry) on a glassy carbon electrode in a DMF solution. Dissolving CO₂ gas into the solution, the cyclic voltammograms displayed an irreversible increase of the cathodic current. This result suggests the catalytic reduction of CO₂. The redox potential (–1.3 V versus Fc/Fc⁺) at which the catalytic behavior was observed is 1.1 V higher than that catalyzed by cobalt tetraphenylporphyrin (CoTPP). The generation number (n) dependence of the dendrimer catalysts showed the maximum activity at n = 3. A significant decrease of the activity for the largest dendrimer (n = 4) indicates a steric effect, which prevents transmission of the substrate (CO₂ molecule) and electrons to the catalytic center (cobalt porphyrin core). For more efficient catalysis, a novel open-shell dendrimer having a pocket on one side of the molecule was designed and synthesized. Because the accessibility to the core in the opened shell improved, this dendrimer exhibited the highest catalytic activity. These results suggest that tuning of the local domain around the cobalt porphyrin center would lead to a decisive solution for further activation of the CO₂ molecule. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5229–5236, 2006