四—(3—甲氧基—4—羟基苯基)卟啉化合物及其钴配合物的合成、鉴定和催化氧化活性

合成了四—(3—甲氧基—4—羟基苯基)卟啉及其金属钴配合物,并用元素分析,H NMR UV、IR及DSC谱进行了结构表征,通过在所合成的钴卟啉配合物存在时氢醌的氧化反应和硫醇化反应,表明它具有催化活性。     

二乙胺基尾式卟啉钴的合成及其载氧性质

合成了1种新的尾式卟啉钴--间-[邻-(4-二乙胺基丁酰胺基)苯基]三苯基卟啉合钴(Ⅱ)配合物,测定了电子光谱、红外光谱、质谱、电子自旋波谱,研究了这种尾式卟啉钴与有机碱和双原子小分子CO、NO的轴向反应及其可逆载氧性质.     

α,β,γ,δ—四苯基卟啉与钴显色反应的研究

用卟啉类显色剂测定钴的研究还较少,而且已报道的均为水溶性卟啉。鉴于非水溶性卟啉合成及提纯容易、产率高、种类多等优点,本文在研究非水溶性α,β,γ,δ-四苯基卟啉(简称TPP)与Cu(Ⅱ)、Pd(Ⅱ)、Cd(Ⅱ)等配合反应的基础上又研究了该试剂与Co(Ⅱ)的反应。在阴离子表面活性剂十二烷基硫酸钠(SDS)存在下,利用咪唑加速催化Co(Ⅱ)对Cd-TPP配合物的置换反应,使Co(Ⅱ)与TPP形成了很稳定的配合物。ε_(435)=3.02×10~5L·mol~(-1)·cm~(-1)。是目前卟啉类试剂测定钴较灵敏的方法,测定维生素B_(12)中钴,结果满意。     

卟啉化合物的研究 Ⅵ.双环双金属钴卟啉的合成

金属卟啉配合物对氧还原反应有良好的电催化活性,是一种高效的氧还原反应催化剂.查全性等的研究表明,四对甲氧苯基钴卟啉配合物对氧还原反应有很好的电催化活性和稳定性,是适用于广泛pH范围的氧化还原反应催化剂.Collman等发现双环双金属卟啉配合物比单环单金属卟啉的催化活性好,这可能是由于两个卟啉环和两个中心金属离子协同作用的结果.Collman和Anson等合成了一系列“面-面”双环双金属卟啉配合物,并用于催化氧还原反应,发现它们可催化氧还原的四电子反应,将氧分子直接还原成水,可极大限度地     

钴卟啉的合成及其对氧还原的电催化性能

 合成了四苯基卟啉及其钴配合物,考察了催化剂、溶剂及反应温度等因素对四苯基卟啉收率的影响,并用红外光谱和核磁共振氢谱对合成产物进行了结构表征. 以X射线光电子能谱为主要手段,研究了不同热处理温度对钴卟啉结构的影响,通过测定空气电极极化曲线研究了热处理对钴卟啉催化活性的影响. 结果表明,在200 ℃, 以对硝基苯甲酸为催化剂,硝基苯为溶剂时,四苯基卟啉收率达32%. 热处理能提高金属卟啉的催化活性, 600 ℃热处理后,钴卟啉环中的 Co-N4 结构趋于键断裂的临界状态,催化活性点增多,催化活性较好; 而800 ℃处理的钴卟啉中部分 Co-N4 键破裂,催化活性下降.     

二吡啶四硝基酞菁钴的合成及光谱—电化学性质研究

本文报道了以钼酸铵为催化剂,将4—硝基邻苯二甲酸酐、脲和氯化铵混合,于220℃加热合成四硝基酞菁钴,将此配合物溶于吡啶,于115℃加热反应6天合成了二吡啶四硝基酞菁钻配合物。并对二吡啶四硝基酞菁钴的氧化还原半波电势、电解氧化还原产物的电子吸收光谱进行了研究。     

四萘基四苯并卟啉钴的合成,表征和电化学行为

合成了四萘基四苯并卟啉钴配合物（ＴＮＴＢＰＣｏ）．用元素分析、紫外可见光谱、红外光声光谱，核磁共振氢谱、摩尔电导进行了表征．用循环伏安法研究了ＴＮＴＢＰＣｏ的电化学性质．结果表明，钴卟啉配合物中心离子由正三价还原为正二价的半波电位为－０．２５５Ｖ，由正二价还原为正一价的半波电位为－１．１７５Ｖ，卟啉环还原的半波电位为－１．８５０Ｖ，三步电极反应均可逆．     

钴(Ⅱ)配合物与卟啉在超临界二氧化碳中的反应动力学研究

用紫外-可见光谱研究了1,1,1,5,5,5-六氟-2,4-戊二酮-钴(Ⅱ)二水[Co(hfac)2(H2O)2]与5,10,15,20-四(五氟苯基)卟啉(H2tpfpp)在超临界二氧化碳中反应生成钴卟啉[Co(tpfpp)]的反应动力学.在钴(II)配合物大大过量时,此反应对卟啉为一级,且其表观一级速率常数随钴(Ⅱ)配合物的浓度增加先增加、而后趋于稳定.根据实验事实,讨论了此反应的机理,得到了相应的热力学和动力学参数.     

尾式缬氨酸四苯基卟啉锌(Ⅱ)与咪唑轴配反应的光谱和热力学

用金属卟啉化合物来模拟血红素、细胞色素等天然卟啉化合物的生理过程一直是配位化学重要的研究课题。人们发现 ,血红蛋白中的血红素是通过铁与组氨酸残基的侧链咪唑配位于蛋白质上 ,因此 ,人们对金属卟啉与咪唑类配体的轴向配位反应研究产生了极大兴趣 [1] 。有关取代四苯基卟啉金属配合物的合成和轴配反应热力学研究已有很多报道 ,但人们的研究尚处在对称且苯环上连有较小取代基的四苯基卟啉锌、钴、铁等模拟化合物的合成、结构表征及光谱和配位反应热力学的研究阶段 [2 -4 ]。对于结构不对称且卟啉中苯环上连有氨基酸的四苯基卟啉配合物…     

CO2电催化还原的研究 IV: 光透薄层电极(OTTLE)研究反应机理

本文用薄层电极的光谱电化学技术, 确定了催化剂碘化四[4-(三甲铵基)苯基]卟啉合钴(Co TMAPI)当恒电位控制在0.6-0.3, -1.0V时分别得以一价, 二价, 三价中心离子的可见紫外光谱, 检测到在咪唑存在下, CO2与一价钴卟啉生成的配合物, 并用易于与一价钴卟啉配位的碘甲烷来进一步证实, 从而肯定了CO2的电催化还原是通过形成CO2配合物中间体的反应途径。     

A Highly Oxidized Cobalt Porphyrin Dimer: Spin Coupling and Stabilization of the Four‐Electron Oxidation Product

A highly oxidized cobalt porphyrin dimer is reported. Each cobalt(II) ion and porphyrin ring underwent 1e oxidation with iodine as the oxidant to give a 4e‐oxidized cobalt(III) porphyrin π‐cation radical dimer. The bridging ethylene group allows for substantial conjugation of the porphyrin macrocycles, thus leading to a strong antiferromagnetic coupling between the π‐cation radicals and to stabilization of the singlet state. X‐ray crystallography clearly showed that the complex may be considered as a real supramolecule rather than two cobalt(III) porphyrin π‐cation radicals that interact through space.     

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.     

长碳链季铵类卟啉钴配合物的合成及其LB膜和气敏性质

四－（4－N，N，N－二甲基）卟啉（TDMAPP）与溴代正十六烷反应得到溴化四－（4－N，N，N－二甲基，十六烷基氨基苯）卟啉（TDMHAPPBr)并制得其钴的配合物，两者均具有良好的成膜性。电子吸收光谱表明LB膜与成膜前固体物分子排列规整性不同，钴配合物对敢有较好的敏感性和良好的选择性，其响应和恢复时间都较短。     

Living radical polymerization of acrylates and acrylamides mediated by a versatile cobalt porphyrin complex

Living radical polymerization (LRP) of organic and water soluble acrylates and acrylamides was mediated by a versatile cobalt porphyrin complex (TMP-OH)Co. The capability of this cobalt complex to mediate LRP in both polar and non-polar media permits the direct synthesis of useful and previously difficult to prepare functional block copolymers.     

Long rod-like array of bis(imidazolyl)porphyrinatocobalt(III) by successive complementary coordination

Simple bis(imidazolyl)porphyrin cobalt(III) complex was found to form a long polymeric array by complementary coordination of imidazole to cobalt ion. Formation of higher ordered assemblies was also observed.     

Electrocatalytic reduction of molecular oxygen at electrodes coated with a new cobalt(II)–platinum(II) bimetallic porphyrin

Cobalt(II) inserts into 5-(4-pyridyl)-10,15,20-(3,4-dimethoxyphenyl)porphyrin (1) by reaction of the porphyrin with the cobalt(II) acetate salt in refluxing N,N′-dimethylformamide solutions. When the porphyrin and the cobalt porphyrin are reacted with PtCl₂(DMSO)₂ in dichloromethane at ambient temperatures the platinum complex coordinates to the peripheral pyridyl group of the porphyrin. Roughened EPG electrodes coated with the cobalt(II)–platinum(II) bimetallic porphyrin, complex (4), show a 500?mV shift in the reduction of molecular oxygen in acidic media when compared to the bare electrode. Oxidation of the bimetallic porphyrin coated electrodes at 1.20?V versus saturated calomel electrode (SCE) results in an additional shift of ca 100?mV for the reduction of molecular oxygen when compared to the bimetallic porphyrin coated electrode prior to oxidation. In addition the oxidized surface shows the ability to reduce approximately 50% of the oxygen to water and the other 50% to hydrogen peroxide according to rotating disk electrode measurements.     

Self-assembly of oligomeric porphyrin rings

A cobalt porphyrin equipped with two different but geometrically complementary pyridine ligands self-assembles to form an unusually stable complex with approximately 12 porphyrin monomers arranged in a macrocyclic array.     

Encapsulation of Metalloporphyrins in a Self‐Assembled Cubic M8L6 Cage: A New Molecular Flask for Cobalt–Porphyrin‐Catalysed Radical‐Type Reactions

The synthesis of a new, cubic M₈L₆ cage is described. This new assembly was characterised by using NMR spectroscopy, DOSY, TGA, MS, and molecular modelling techniques. Interestingly, the enlarged cavity size of this new supramolecular assembly allows the selective encapsulation of tetra(4‐pyridyl)metalloporphyrins (M^II(TPyP), M=Zn, Co). The obtained encapsulated cobalt–porphyrin embedded in the cubic zinc–porphyrin assembly is the first example of a catalytically active encapsulated transition‐metal complex in a cubic M₈L₆ cage. The substrate accessibility of this system was demonstrated through radical‐trapping experiments, and its catalytic activity was demonstrated in two different radical‐type transformations. The reactivity of the encapsulated Co^II(TPyP) complex is significantly increased compared to free Co^II(TPyP) and other cobalt–porphyrin complexes. The reactions catalysed by this system are the first examples of cobalt–porphyrin‐catalysed radical‐type transformations involving diazo compounds which occur inside a supramolecular cage.     

Asymmetric cyclopropanation of styrenes catalyzed by metal complexes of D2-symmetrical chiral porphyrin: superiority of cobalt over iron

The cobalt(II) complex of D2-symmetric chiral porphyrin [Co(1)] is an effective catalyst for highly diastereoselective and enantioselective cyclopropanation of a broad range of styrene derivatives under mild conditions. Dimerization of diazo compounds, a common side reaction in metal-mediated carbene transfer processes, is minimized in a cobalt porphyrin-based system, obviating the need to employ excess substrates and slow addition of diazo compounds. The high catalytic activity and selectivity of [Co(1)] evidently resulted from the appropriate combination of the cobalt ion and the chiral porphyrin 1 as the use of iron(III) complex of the same ligand [Fe(1)Cl] afforded the desired cyclopropane products in low yields and poor enantioselectivity.