键联聚乙二醇高分子担载锰（Ⅲ）卟啉的合成及催化烯烃环氧化反应性能研究

本文研究了键联聚乙二醇高分子担载锰（Ⅲ）卟啉的合成，以及在ＣＨ_２Ｃｌ_２／Ｈ_２Ｏ两相体系中催化苯乙烯环氧化反应的性能．探索了催化反应体系中溶液ｐＨ值、ＮａＯＣｌ浓度、轴向配体及相转移催化剂对催化反应的影响．结果说明键联聚乙二醇高分子担载锰（Ⅲ）卟啉是烯烃环氧化反应的一种有效催化剂，其中聚乙二醇链可以络合Ｎａ，使ＯＣｌ富集于金属卟啉周围，起到较好的相转移催化作用．在催化反应的各影响因素中，水相ｐＨ值对反应的影响最大．     

钴基催化剂上乙烷氧化脱氢的催化作用

比较了氧化钴、氧化镍分别对乙烯、乙烷氧化的催化性能,结果发现：乙烯在氧化钴较氧化镍上更易进一步深度氧化生成CO2．通过对新制担载型Co-基催化剂随反应温度反复升、降温的乙烷氧化脱氢(ODHE)性能研究,展现了氧化钴活性相与SiO2载体相互作用对催化性能的影响．Weiss原位磁研究结果表明：SiO2担载的氧化钴催化剂较难还原,即使在反应气中氧被完全耗完时,钴仍停留在Co^2 的价态上．通过对数十个担载和未担载、不同载体、不同担载量的Co-基催化剂的ODHE性能考察表明：在Co-基催化剂上ODHE反应机理一般遵从Hetero-homogeneous机理．     

天然高分子负载型钯催化剂的表征及在催化苯乙烯氢酯基化反应中的重复使用

用SiO2担载壳聚糖（简写为CS），再负载PdCl2，制得催化剂SiO2-CS-PdCl2，其在苯乙烯及其衍生物的氢酯基化反应中表现出了较高的催化活性和选择性。XPS和TEM数据表明，催化剂的活性组分颗粒以纳米尺寸均匀地分布在载体表面，而且载体CS对金属钯有明显的配位作用。在反应体系中加入少量对苯醌，可防止钯聚集成钯黑沉淀而使催化剂失活，改善催化剂的重复使用效果。     

P(4VP-co-St)/SiO2固载的取代钴卟啉对乙苯的催化氧化性能

通过轴向配位法将不同结构的钴卟啉(CoTXPP(X=H, Cl, NO2))分别固载到接枝微粒聚(4-乙烯基吡啶-co-苯乙烯)/SiO2(P(4VP-co-St)/SiO2)上, 室温下分别制备了P(4VP-co-St)/SiO2固载的金属卟啉催化剂CoTPP-P(4VP-co-St)/SiO2, CoTClPP-P(4VP-co-St)/SiO2和CoTNPP-P(4VP-co-St)/SiO2, 利用傅立叶变换红外(FTIR)光谱和电子吸收光谱对其结构及轴配过程进行了表征. 在无溶剂、无助催化剂和还原剂的体系中, 研究对比了其催化分子氧氧化乙苯为苯乙酮的性能, 考察了不同反应条件对苯乙酮产率的影响. 研究发现, 其催化活性随着环外取代基吸电子能力的增强而提高. CoTNPP-P(4VP-co-St)/SiO2的催化活性和选择性最好, 在120 ℃常压下其催化乙苯反应12 h, 苯乙酮收率达到25.53%, 产物α-甲基苄醇的含量则极少. 与普通的催化剂不同, 在催化氧化体系中, CoTNPP-P(4VP-co-St)/SiO2存在最适宜用量, 过量的CoTNPP-P(4VP-co-St)/SiO2反而会使其催化活性降低; P(4VP-co-St)/SiO2表面CoTXPP的固载密度存在一最佳值. 此外, 固载化以后, 催化剂具有较好的重复使用性. 结果表明, 接枝微粒P(4VP-co-St)/SiO2对金属卟啉不仅有明显的保护作用, 而且能提高其稳定性.     

键联聚乙二醇高分子担载锰（Ⅲ）卟啉的合成及催化烯烃环氧化反应性…

本文研究了键联聚乙二醇高分子担载锰（Ⅲ）卟啉的合成，以及在ＣＨ２Ｃｌ２／Ｈ２Ｏ两相体系中催化苯乙烯环氧化反应的性能，探索了催化反应体系中溶液ｐＨ值、ＮａＯＣｌ浓度、轴向配体及相转移催化剂对催化反应的影响。结果说明键联聚乙二醇高分子担载锰（Ⅲ）卟啉是烯烃环氧化反应的一种有效催化剂，其中聚乙二醇链可以络合Ｎａ，使ＯＣｌ富集于金属卟啉周围，起到较好的相转移催化作用。在催化反应的各影响因素中，水相ｐＨ值对     

丙烷选择氧化用VPO／SiO2催化剂的研究

 摘要：对比研究了VPO和VPO／SiO2催化剂的结构、表面元素氧化态、还\r\n原性及其对丙烷选择氧化反应的催化性能．与VPO催化剂相比，VPO／S\r\niO2催化剂具有较大的比表面积；VPO主要以（VO）2P2O7的形式高度分散于SiO2表面；VPO／SiO2催化剂的还原温度较低；VPO／SiO2催化剂与丙烷的相互作用较强；在反应条件下，VPO／SiO2催化剂的活性较高，但产物丙烯的选择性较低，并有丙烯醛等C3含氧化合物生成．这可能是由于VPO／SiO2催化剂表面的V与Si发生了相互作用之故．随着VPO担载量的增加，VPO／SiO2催化剂的比表面积减小；催化剂的还原温度略有升高，可还原的晶格氧量增加；催化剂表面与丙烷的相互作用增强；丙烷转化率升高而丙烯选择性降低，丙烯醛选择性在5％VPO／SiO2催化剂上最高．这可能是由于随着VPO担载量的增加，催化剂表面晶格氧的密度增大所致．     

SnO2—SiO2负载Cu,Ni催化剂的CO2加氢反应性能

采用表面反应改性法制备了SnO2-SiO2(SnSIO)表面复合物载体,用等体积浸渍法制备了SnSiO担载的Cu-Ni双金属催化剂,借助BFT,XRD,TPR,IR和微反等技术研究了SnSiO及其负载的Ni,Cu双金属催化剂的表面构造,化学吸附及CO2加氢反应性能,结果表明：SnSiO是SnO2单分子层价联于SiO2表面的复合氧化物,仍保持类似SiO2载体的孔结构和比表面;SnO2引入SiO2表面后可以有效地促进CuO,NiO的还原,还原后成为负载在SnSiO载体表面的Cu-Ni合金,CO2在负载型Cu-Ni合金表面Cu或表面Ni位 发生化学吸附,形成线式和剪式吸附;CO2在催化剂上的加氢反应产物主要是CH3OH,CH4,CO和H2O,生成CH3OH的选择性与催化剂组成及反应条件密切相关,Cu-Ni催化剂,在0．5MPa,170度,H2。CO2（mol/mol)为3 的条件下,CH3OH的选择性达到84．6％。     

担载金属簇的研究——Ⅵ.担载Ti—Co羰基金属簇的合成和加压原位红外光谱

将双(环戊二烯基)二氯化钛(Cp_2TiCl_2)负载到聚苯乙烯载体上,再与Co_2(CO)_8反应,合成了三种担载的准异核羰基金属簇p(?)CH_2 Cp_2Ti(Cl)OCCo_3(CO)_9。用IR表征结构并研究担载金属簇的热稳定性、乙烯氢甲酰化反应的催化性能及反应机理。     

可动氧与载体对钴基催化剂的乙烷氧化脱氢性能的影响

 报道了未担载的氧化钴与担载在SiO2和Al2O3上的氧化钴的乙烷氧化脱氢行为,发现未担载的氧化钴在150℃的低温下就有活性．XRD研究表明,Co3O4为活性晶相组分,其含量与催化剂的焙烧温度密切相关,经500℃和1000℃焙烧的未担载的氧化钴中Co3O4晶相分别占100％和66％．对于担载型氧化钴催化剂,载体与氧化钴间的相互作用以及不同的氧化钴担载量导致催化性能发生明显改变．氧化钴与载体间的作用越强,催化活性越低．Co3O4也是担载型氧化钴催化剂的活性晶相．催化剂的O2－TPD－MS和H2－TPR研究结果表明,反应的活性氧物种为在低温下易脱除和易还原并具有较高流动性的可动氧．     

单分散SiO2的焙烧温度对Rh基催化剂上CO加氢反应性能的影响

在比较了分别以商业SiO2和采用Sto?ber法制备的单分散SiO2为载体的Rh-Mn-Li/SiO2催化剂催化CO加氢反应性能的基础上,进一步调变了Stober法制备SiO2时的焙烧温度,并考察了其对Rh-Mn-Li/SiO2催化CO加氢性能的影响.利用N2吸附-脱附、傅里叶变换红外(FTIR)光谱、H2程序升温还原(H2-TPR)、程序升温表面反应(TPSR)等方法对载体及催化剂的物理化学性能进行了表征.结果表明:不同温度焙烧的载体表面具有不同的Si―OH数量,从而影响金属的分散状态及Rh和Mn之间的相互作用.载体表面较多的羟基有利于Rh的分散和CO的吸附,从而增强催化剂的反应活性.载体表面适当数量的羟基能够得到适中的Rh与Mn之间的相互作用,使催化剂具有合适的CO解离能力,有利于CHx的CO插入反应,从而提高了C2含氧化合物的选择性.     

Remarkable CO-catalyst effect of gold nanoclusters on olefin oxidation catalyzed by a manganese-porphyrin complex

The effect of dodecanethiolate-protected metallic nanoclusters of gold (Au:SC12, 1), silver (Ag:SC12), palladium (Pd:SC12), and platinum (Pt:SC12) on the catalytic activity of Mn(TPP)Cl (TPP = tetraphenylporphinato) was investigated in styrene oxidation with iodosylbenzene. Among the four metal clusters, only Au:SC12 led to appreciable acceleration of the catalytic reaction. The major role of the Au cluster was to regenerate the active catalytic path involving Mn(III) and Mn(V) from the deactivated Mn(IV) species. The binary 1/Mn(TPP)Cl catalyst system showed an absorption spectrum characteristic of Mn(III)-porphyrin after reaction, whereas a catalytically ineffective Mn(IV) species was observed as the sole porphyrin species in the absence of the Au cluster or in the presence of Pd, Ag, and Pt clusters. Accordingly, the slow oxidation reaction with Mn(TPP)Cl was accelerated by the addition of Au:SC12, and complete conversion of Mn(IV) into Mn(III) was observed in the absorption spectrum. 1H NMR inspection of the reaction of Au:SC12 and iodosylbenzene revealed that the surface dodecyl groups were partially oxidized into dodecanal and eliminated from the cluster surface, thereby producing unprotected gold sites on the surface. A reactivation mechanism involving the reaction of the Mn-porphyrin and the oxidant activated on the gold surface is proposed.     

Biomimetic epoxidation of alkenes with sodium periodate catalyzed by tetraphenylporphyrinatomanganese(III) chloride supported on multiwall carbon nanotubes

The biomimetic epoxidation of alkenes catalyzed by tetraphenylporphyrinatomanganese(III) chloride, [Mn(TPP)Cl], immobilized on multiwall carbon nanotubes modified with 4-aminopyridine and 4-aminophenol is reported. These heterogenized catalysts were used as efficient and reusable catalysts for epoxidation of a variety of cyclic and linear alkenes with sodium periodate under mild conditions. The catalysts, [Mn(TPP)Cl@amine-MWCNT], were characterized by physico-chemical and spectroscopic methods. The effect of ultrasonic irradiation on these catalytic systems was also investigated. The catalysts were reused several times without loss of their activity.     

Structure and catalytic activity of a manganese(III) tetraphenylporpholactone

A manganese(III) complex of tetraphenylporpholactone, Mn(TPPL)Cl, was synthesized and characterized, including by single-crystal X-ray diffraction; the catalytic activity of this complex for olefin epoxidation reactions is compared with that of manganese(III) tetraphenylporphyrin chloride, Mn(TPP)Cl.     

Green oxidation of 2-imidazolines with tert-butyl hydroperoxide catalyzed by supported manganese(III) porphyrin in water

Green oxidation of 2-substituted imidazolines with tert-butyl hydroperoxide catalyzed by tetraphenylporphyrinatomanganese(III) chloride, [Mn(TPP)Cl], supported on polystyrene and silica bound imidazole is reported. A variety of 2-imidazolines were efficiently converted to their corresponding imidazoles by these catalytic systems in H₂O. Ultrasonic (US) irradiation enhanced the catalytic activity of these catalysts and higher product yields were observed at shorter reaction times. These catalysts were re-used several times without significant loss of their catalytic activities. The effect of reaction parameters such as catalyst amount, reaction temperature, and the effect of US irradiation on the catalytic activity was also investigated.     

Laser flash photolysis generation and kinetic studies of porphyrin-manganese-oxo intermediates. Rate constants for oxidations effected by porphyrin-Mn(V)-oxo species and apparent disproportionation equilibrium constants for porphyrin-Mn(IV)-oxo species

Porphyrin-manganese(V)-oxo and porphyrin-manganese(IV)-oxo species were produced in organic solvents by laser flash photolysis (LFP) of the corresponding porphyrin-manganese(III) perchlorate and chlorate complexes, respectively, permitting direct kinetic studies. The porphyrin systems studied were 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPFPP), and 5,10,15,20-tetrakis(4-methylpyridinium)porphyrin (TMPyP). The order of reactivity for (porphyrin)Mn(V)(O) derivatives in self-decay reactions in acetonitrile and in oxidations of substrates was (TPFPP) > (TMPyP) > (TPP). Representative rate constants for reaction of (TPFPP)Mn(V)(O) in acetonitrile are k = 6.1 x 10(5) M(-1) s(-1) for cis-stilbene and k = 1.4 x 10(5) M(-1) s(-1) for diphenylmethane, and the kinetic isotope effect in oxidation of ethylbenzene and ethylbenzene-d(10) is k(H)/k(D) = 2.3. Competitive oxidation reactions conducted under catalytic conditions display approximately the same relative rate constants as were found in the LFP studies of (porphyrin)Mn(V)(O) derivatives. The apparent rate constants for reactions of (porphyrin)Mn(IV)(O) species show inverted reactivity order with (TPFPP) < (TMPyP) < (TPP) in reactions with cis-stilbene, triphenylamine, and triphenylphosphine. The inverted reactivity results because (porphyrin)Mn(IV)(O) disproportionates to (porphyrin)Mn(III)X and (porphyrin)Mn(V)(O), which is the primary oxidant, and the equilibrium constants for disproportionation of (porphyrin)Mn(IV)(O) are in the order (TPFPP) < (TMPyP) < (TPP). The fast comproportionation reaction of (TPFPP)Mn(V)(O) with (TPFPP)Mn(III)Cl to give (TPFPP)Mn(IV)(O) (k = 5 x 10(8) M(-1) s(-1)) and disproportionation reaction of (TPP)Mn(IV)(O) to give (TPP)Mn(V)(O) and (TPP)Mn(III)X (k approximately 2.5 x 10(9) M(-1) s(-1)) were observed. The relative populations of (porphyrin)Mn(V)(O) and (porphyrin)Mn(IV)(O) were determined from the ratios of observed rate constants for self-decay reactions in acetonitrile and oxidation reactions of cis-stilbene by the two oxo derivatives, and apparent disproportionation equilibrium constants for the three systems in acetonitrile were estimated. A model for oxidations under catalytic conditions is presented.     

Crystallographic identification of a series of manganese porphyrin complexes with nitrogenous bases

Studying the axial ligation behavior of metalloporphyrins with nitrogenous bases helps to better understand not only the biological function of heme‐based protein systems, but also the catalytic properties of porphyrin‐based reaction sites in other biomimetic synthetic support environments. Unlike iron porphyrin complexes, little is known about the axial ligation behavior of Mn porphyrins, particularly in the solid state with Mn in the +3 oxidation state. Here, we present the syntheses and crystal and molecular structures of three new high‐spin manganese(III) porphyrin complexes with the different amine‐based axial ligands imidazole (im), piperidine (pip), and 1,4‐diazabicyclo[2.2.2]octane (DABCO), namely bis(imidazole)(5,10,15,20‐tetraphenylporphyrinato)manganese(III) chloride chloroform disolvate, [Mn(C₄₄H₂₈N₄)(C₃H₄N₂)₂]Cl·2CHCl₃ or [Mn(TPP)(im)₂]Cl·2CHCl₃ (TPP = 5,10,15,20‐tetraphenylporphyrin), (I), bis(piperidine)(5,10,15,20‐tetraphenylporphyrinato)manganese(III) chloride, [Mn(C₄₄H₂₈N₄)(C₅H₁₁N)₂]Cl or [Mn(TPP)(pip)₂]Cl, (II), and chlorido(1,4‐diazabicyclo[2.2.2]octane)(5,10,15,20‐tetraphenylporphyrin)manganese(III)–1,4‐diazabicyclo[2.2.2]octane–toluene–water (4/4/4/1), [Mn(C₄₄H₂₈N₄)Cl(C₆H₁₂N₂)]·C₆H₁₂N₂·C₇H₈·0.25H₂O or [Mn(TPP)Cl(DABCO)]·(DABCO)·(toluene)·0.25H₂O, (IV). A fourth complex, chlorido(pyridine)(5,10,15,20‐tetraphenylporphryinato)manganese(III) pyridine disolvate, [Mn(C₄₄H₂₈N₄)Cl(C₅H₅N)]·2C₅H₅N or [Mn(TPP)Cl(py)]·2(py), (III), acquired using different crystallization methods from published data, is also reported and compared to the previous structures.     

Interfacial hydrolysis in the mu-oxo dimer formation of tetraphenylporphinatomanganese(III) in the toluene/water system.

The interfacial adsorption and dimerization behavior of tetraphenylporphinatomanganese(III)chroride (Mn(TPP)Cl) in the toluene/water two phase system was studied. The absorption spectra of the porphyrin complex in the organic phase were blue shifted with increasing of pH in the aqueous phase, suggesting the formation of the mu-oxo dimer. The interfacial species in these systems were examined by means of UV/vis external reflection (ER) spectrophotometry. ER spectral maxima were also blue shifted with the increase in pH, whereas the shape of the ER spectra in the basic conditions was different from that of the mu-oxo dimer. The observed results suggest that the hydroxide-coordinated monomer, Mn(TPP)OH, was generated from the Mn(TPP)(H2O)+ at the interface under the basic conditions and that was further converted to the mu-oxo dimer, which was soluble into the toluene phase.     

Water increases rates of epoxidation by Mn(III)porphyrins/imidazole/IO4(-) in CH2Cl2. Analogy with peroxidase and chlorite dismutase

Manganese(III)-meso-tetraphenylporphyrin [Mn(TPP)] and manganese(III)-meso-tetrakis(pentafluorophenyl)porphyrin [Mn(TPFPP)] catalyse the epoxidation of cyclooctene by IO(4)(-) in the presence of excess imidazoles, in both dry CH(2)Cl(2) and CH(2)Cl(2) saturated with H(2)O. The reaction rates of the electron deficient Mn(TPFPP) are a factor 24 less than those of Mn(TPP); however, the former increases 15-30 times in the presence of water, while those of Mn(TPP) do so by a factor of 2-3. The most striking catalytic enhancement caused by the addition of water was observed with 2-methylimidazole and Mn(TPFPP). As deprotonation of imidazoles may play a significant role in the presence of water, we found that manganese(III)-meso-tetrakis(phenyl-4-sulfonato)porphyrin [Mn(TPPS)] decreases the NH proton pK(a) of axially coordinated imidazole from 14.2 to 9.5. We conclude that the imidazole ligand is partially deprotonated in the presence of water. The latter enables the solvation of imidazolium ions that are formed simultaneously. The imidazolate form of the co-catalyst is a much stronger donor than the imidazole itself, providing electron density to Mn(III) and thus promoting oxygen transfer. The failure of N-methylimidazole to increase the reaction rates upon addition of water supports this hypothesis. A functionally related deprotonation has been shown to occur in horseradish peroxidase (J. S. de Ropp, V. Thanabal, G. N. La Mar, J. Am. Chem. Soc. 1985, 107, 8270-8272) and in chlorite dismutase (B. R. Goblirsch, B. R. Streit, J. L. Dubois, C. M. Wilmot, J. Biol. Inorg. Chem. 2010, 15, 879-888). Mn(III)porphyrins in combination with imidazoles and water constitute a functional biomimetic model of peroxidases.     

模拟细胞色素P-450和仿生氧化反应研究III. 有关用TPPFe(III)Cl及TPPMn(III)Cl催化的环己烷充氧化反应机理的初步探讨

本文研究了ArIO充氧化环己烷的反应体系。在TPPFe(III)Cl及TPPMn(III)Cl催化下进行了动态UV-Vis谱和ESR分析,提出了二种催化体系可能由二种不同递氧中间体的反应机理。     

苯环上氯取代位对四苯基金属卟啉催化烯烃环氧化性能的影响

以苯乙烯、环己烯和反式二苯乙烯为烯烃底物,以双氧水、叔丁基过氧化氢和异丙苯过氧化氢为氧化剂,以苯环上对位和邻位氯取代的四苯基金属卟啉为仿生催化剂,对烯烃的催化环氧化反应进行了对比研究.讨论了不同氯取代位的四苯基金属卟啉对烯烃环氧化性能的影响.实验结果表明,在没有助催化剂存在下,邻位氯代的四(2,6-二氯苯基)铁(锰)卟啉对烯烃的环氧化具有优异的催化性能,烯烃底物的转化率和环氧选择性都比对位氯代的四苯基铁(锰)卟啉高,且反应条件温和.其中FeⅢ(TDCPP)Cl的催化性能最好,环氧化选择性最高,催化氧化苯乙烯时,环氧苯乙烷的选择性达到了90.4%.相同金属离子不同配体的金属卟啉传递氧原子的能力为TDCPP>T(p-Cl)PP>TPP.氧化剂的结构对环氧化物的选择性有较大影响.过氧键连有吸电子基团的异丙苯过氧化氢对环氧化物的选择性最高.根据实验结果,对金属卟啉催化环氧化机理进行了分析.