Highly Soluble Porphyrin (TPP)-Perylene Diimide (PDI) Dyad and Triad:Synthesis and Spectroscopic Studies

Novel porphyrin‐perylene diimide dyad (TPP‐PDI) and porphyrin‐perylene diimide‐porphyrin triad (TPP‐PDI‐TPP) were synthesized and characterized. Their structure and properties were studied by UV, FL, ¹H NMR, MS, elemental analysis, etc. The variation of fluorescence feature and UV spectra of TPP‐PDI‐TPP triad were investigated at different concentration of CF₃COOH in THF. The incorporation of CF₃COOH leads to the closure of the efficient charge transfer decay. After protonation of porphyrin units, the fluorescence intensity of TPP‐PDI‐TPP triad increased greatly. The fluorescence intensity of TPP‐PDI‐TPP triad restored after addition of triethylamine into the solution. Thus, TPP‐PDI‐TPP triad was a proton‐type fluorescence switch based on acid‐base control. Moreover, different from porphyrin‐perylene type molecular switches reported before, this TPP‐PDI‐TPP triad has wonderful solubility in organic solvents.     

One-Pot Functionalization of Graphene with Porphyrin through Cycloaddition Reactions

Two types of graphene‐based hybrid materials, graphene‐TPP (TPP=tetraphenylporphyrin) and graphene‐PdTPP (PdTPP=palladium tetraphenylporphyrin), were prepared directly from pristine graphene through one‐pot cycloaddition reactions. The hybrid materials were characterized by thermogravimetric analysis (TGA), by TEM, by UV/Vis, FTIR, Raman, and luminescence spectroscopy, and by fluorescence/phosphorescence lifetime measurements. The presence of the covalent linkages between graphene and porphyrin was confirmed by FTIR and Raman spectroscopy and further supported by control experiments. The presence of TPP (or PdTPP) in the hybrid material was demonstrated by UV/Vis spectroscopy, with TGA results indicating that the graphene‐TPP and graphene‐PdTPP hybrid materials contained approximately 18 % TPP and 20 % PdTPP. The quenching of fluorescence (or phosphorescence) and reduced lifetimes suggest excited state energy/electron transfer between graphene and the covalently attached TPP (or PdTPP) molecules.     

四苯基卟啉制法的改进

传统合成四苯基卟啉(简称H_2TPP)的方法是将吡咯与等摩尔苯甲醛在丙酸中进行回流,产率仅20%,制得的H_2TPP中含3%～10%四苯基二氢卟啉(简称TPC),分离十分因难。 本文报道以丙酸为主的混合溶剂,并用亚硫酰氯代替过去采用的,毒性大的2,3-二氯-5,6-二氰苯醌作氧化剂进行氧化处理。H_2TTP产率达60%以上,纯化物收率38%。     

Synthesis and Photocytotoxicity of Mono-functionalised Porphyrin with Valine Moiety

A mono-funtionalised tetraphenylporphyrin (TPP) bearing valine moiety at the phenyl ring was synthesized for photocytotoxicity examination in four steps, starting from regiospecific mono-nitration of TPP at the phenyl ring. The in vitro photocytotoxicitic effect against SPC-Al adenocarcinona cell line was tested.     

金属卟啉的直接电化学合成及其固体微粒伏安行为研究

用固体微粒伏安法在电极表面直接获得了铜卟啉、铁卟啉及钴卟啉,在氯化钾支持电解质溶液中用循环伏安法对meso四苯基卟啉(H₂TPP)及现场合成的金属卟啉的固体电化学行为进行了表征.作为电荷补偿,实验证明在固体金属卟啉还原及氧化过程中同时伴随有钾离子在晶胞中的迁移,文中对金属卟啉的形成机理及其电极反应机理进行了详细探讨.     

丝状液晶5CB与铁(Ⅲ)卟啉之间的轴向配位作用

通过考察掺杂配位性质不同的两种铁(Ⅲ)卟啉的丝状液晶5CB在磁场下的行为以及UV-Vis光谱,研究了液晶5CB与铁(Ⅲ)卟啉的轴向配位作用.结果表明,弗雷德里克兹转变阈值的降低和Soret带随着液晶5CB含量增大而红移是液晶5CB与五配位Fe(TPCl发生轴向配位的结果.     

卟啉作为信号传递介质的紫外可见光谱研究

合成了6种氨基酸水杨醛席夫碱(Sal-AA)：Sal-Gly(甘氨酸)、Sal-Phe(苯丙氨酸)、Sal-Arg(精氨酸)、Sal-Tyr(酪氨酸)、Sal-Met(甲硫氨酸)、Sal-Glu(谷氨酸)及其金属铜配合物。并分别在2种不同介质(三氯甲烷和甲醇)中，与四苯基卟啉TPP进行反应，研究了其紫外可见光谱性质，讨论了卟啉作为人工信号转导体系的传递介质，与氨基酸水杨醛席夫碱铜配合物的反应中，实现信号分子铜离子进一步传递的可能性以及溶剂对该信号传递的影响。结果表明，在三氯甲烷为溶剂时，除了Sal-Met的铜配合物之外，其余均能被TPP夺取而形成Metal TPP。而在以甲醇为溶剂时，只有Sal-Gly的铜配合物能被TPP所夺取。     

Rare earth–porphyrin complex catalysts for transforming CO2 into cyclic carbonate under mild conditions

A series of rare earth metal complexes RE(TPP)(acac) (RE = Nd^III, Yb^III, Eu^III, Er^III, Pr^III, and Lu^III; TPP = 5,10,15,20-tetraphenylporphyrin) were synthesized and characterized via UV–vis, IR, and elemental analyses. Their catalytic activities on the synthesis of cyclic carbonates from carbon dioxide and epoxides under different reaction conditions (temperature, pressure, and reaction time) were investigated. Catalytic reaction tests showed that the complex Lu(TPP)(acac) could significantly enhance the catalytic reactivity under mild conditions without any co-solvent.     

PHOTO-ASSISTED ELECTRON TRANSFER IN A NICKEL(II) PORPHYRIN COMPLEX: FORMATION OF NICKEL(III)-PORPHYRIN π-CATION RADICAL

Abstract

In sunlight the complex Ni^II(TPP) {TPP=tetraphenylporphyrin} undergoes photolysis in CH₂Cl₂ to produce a stable nickel porphyrin π-cation radical [Ni^IITPP?]⁺ species which has been characterised by epr measurement.     

锌卟啉轴向配合物的光谱特性及配位二聚体分子内的能量传递

通过轴向配位作用构造了ZnTPP-H₂(m-py)TPP卟啉二元体系,研究了配位二聚体的可见吸收光谱和荧光发射光谱特性,考察了二聚体分子内的能量传递过程,观察到能量从激发态ZnTPP^*流向H₂(m-py)TPP。作为对比,研究了ZnTPP-py体系的可见吸收光谱和荧光发射光谱。轴向配位的吡啶引起了ZnTPP荧光光谱明显红移,没有分子内的能量转移过程发生。用吸收光谱和荧光光谱方法计算了加合反应的平衡常数,得到了基本一致的结果。     

对位取代四苯基卟啉及其铁(Ⅲ)配合物的~1H NMR研究

本文用BRUKER MSL-400型超导核磁共振仪,对于对位取代四苯基卟啉[H_2(p-X)TPP,X=Cl,H,CH_3,OCH_3],对位取代四苯基卟啉铁(Fe(Ⅲ)(p-X)TPPCl)及其轴向配合物([Fe(Ⅲ)(p-X)TPP(HIm)_2]~+Cl~-,([Fe(Ⅲ)(p-CH_3)TPPYm]~+Cl~-,Y=2-CH_3Im,2-C_2H_5-4-CH_3Im,n-C_3H_7NH_2,N(C_2H_5)_3)的质子核磁共振谱进行了较系统的研究,探讨了分子对称性、电子结构、顺磁效应等对~1H NMR谱的影响以及铁卟啉配合物的电子自旋离域机理。     

Styrene polymerization catalyzed by metal porphyrin complex/MAO for in situ synthesizing polystyrene containing air stable π cation radicals

A novel catalyst system based on nickel(II) tetraphenylporphyrin (Ni(II)TPP) and methylaluminoxane for styrene polymerization was developed. This catalyst system has a high thermal stability and show fairly good activity. The obtained polystyrene (PS) was isotactic‐rich atactic polymer by ¹³C NMR analysis, and its molecular weight distribution was rather narrow (M_w/M_n ≈ 1.6, by GPC analysis). ESR revealed that Ni(II)TPP π cation radicals were formed in the polymerization and could remain in the resulting PS stably. The mechanism of the polymerization was discussed and a special coordination mechanism was proposed. The PS product containing Ni(II)TPP π cation radicals can be used as a potential functional material. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1240–1248, 2008     

Microscopy of large-scale porphyrin aggregates formed from protonated TPP dimers in water–organic solutions

Properties of porphyrin aggregates were investigated by absorption spectroscopy (UV–Vis and IR) in water–tetrahydrofuran (THF) solutions in the presence of different concentrations of HCl. The morphology of the aggregates was observed by scanning electron microscopy (SEM) and atomic force microscopy in thin films. A new protonated meso-tetraphenylporphine (TPP) form that shows characteristic absorptions in the UV–Vis spectra was found in the aggregated porphyrin in the presence of 2N HCl. Two types of changes with time were observed in these spectra, one of which is due to sticking together of the porphyrin aggregates. The second is associated with the formation of complexes between the protonated TPP dimer with λ_max=465 nm and metal ions that are probably leached out from the support by the acid. IR spectra of porphyrin aggregates prepared in the presence of different concentrations of HCl show huge water contents in the thin films and different characteristics of the water bound in the aggregates. Porphyrin aggregates prepared at different concentrations of HCl exhibited different surface properties. TPP aggregates prepared in the presence of 0.4N HCl and observed by SEM exhibit smooth surfaces over ranges of several micrometers. TPP aggregates prepared in the presence of 2N HCl form a continuous thin layer with 3–5 μm wide domains that consist of submicroscopic grains. These appear to be the result of 200–400 nm wide spherical particles that stick together.     

Axial Ligand Coordination Tuning of the Electrocatalytic Activity of Iron Porphyrin Electrografted onto Carbon Nanotubes for the Oxygen Reduction Reaction

The oxygen reduction reaction (ORR) is essential in many life processes and energy conversion systems. It is desirable to design transition metal molecular catalysts inspired by enzymatic oxygen activation/reduction processes as an alternative to noble-metal-Pt-based ORR electrocatalysts, especially in view point of fuel cell commercialization. We have fabricated bio-inspired molecular catalysts electrografted onto multiwalled carbon nanotubes (MWCNTs) in which 5,10,15,20-tetra(pentafluorophenyl) iron porphyrin (iron porphyrin FeF₂₀TPP) is coordinated with covalently electrografted axial ligands varying from thiophene to imidazole on the MWCNTs’ surface. The catalysts’ electrocatalytic activity varied with the axial coordination environment (i. e., S-thiophene, N-imidazole, and O-carboxylate); the imidazole-coordinated catalyst MWCNTs-Im-FeF₂₀TPP exhibited the highest ORR activity among the prepared catalysts. When MWCNT-Im-FeF₂₀TPP was loaded onto the cathode of a zinc−air battery, an open-cell voltage (OCV) of 1.35 V and a maximum power density (P_max) of 110 mW cm⁻² were achieved; this was higher than those of MWCNTs-Thi-FeF₂₀TPP (OCV=1.30 V, P_max=100 mW cm⁻²) and MWCNTs-Ox-FeF₂₀TPP (OCV=1.28 V, P_max=86 mW cm⁻²) and comparable with a commercial Pt/C catalyst (OCV=1.45 V, P_max=120 mW cm⁻²) under similar experimental conditions. This study provides a time-saving method to prepare covalently immobilized molecular electrocatalysts on carbon-based materials with structure–performance correlation that is also applicable to the design of other electrografted catalysts for energy conversion.     

Biomimetic Decarboxylation of Carboxylic Acids with PhI(OAc)2 Catalyzed by Manganese Porphyrin [Mn(TPP)OAcl

Manganese(Ⅲ) meso-tetraphenylporphyrin acetate [Mn(TPP)OAc] served as an effective catalyst for the oxidative decarboxylation of carboxylic acids with (diacetoxyiodo)benzene [Phl(OAc)2] in CH2C12-H2O(95:5,volume ratio),The aryl substituted acetic acids are more reactive than the less electron rich linear carboxylic acids in the presence of catalyst Mn(TPP)OAc,In the former case,the formation of carbonyl products was complete within just a few minutes with ＞97% selectivities,and no further oxidation of the produced aldehydes was achieved under these catalytic conditions,This method provides a benign procedure owing to the utilization of low toxic(diacetoxyiodo)benzene,biologically relevant manganese porphyrins,and carboxylic acids.     

强磁场对四苯基卟啉及其Co(Ⅱ)/Zn(Ⅱ)配合物的影响

为研究强磁场对卟啉类化合物的影响,以四苯基卟啉(TPP)为研究对象,比较分析了无外加磁场和强磁场条件下TPP的结晶,及Co~(2+)、Zn~(2+)与TPP的配位反应。采用X射线粉末衍射测试不同磁场强度下获得的TPP晶体,紫外分光光度计快速测定了不同磁场强度下配合物产率,并分析了配位反应的动力学。TPP的结晶度随磁场强度的增强而提高,晶体尺寸随磁场强度的增加而增大;随磁场的增强,四苯基钴卟啉(CoTPP)和四苯基锌卟啉(ZnTPP)的产率下降,但两者的反应动力学不受磁场影响,其反应速率随磁场强度提高而下降。由研究结果可知,强磁场有利于四苯基卟啉的结晶取向,四苯基卟啉在溶液中垂直于磁场取向是配位反应速率降低的主要原因,随磁场强度的增加,四苯基卟啉的取向程度提高。     

[Sn(TPP)(BF4)2]: An efficient and reusable catalyst for chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane

Tin(IV)tetraphenylporphyrinato tetrafluoroborate, [Sn^IV(TPP)(BF₄)₂], was used as an efficient catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS). High-valent [Sn^IV(TPP)(BF₄)₂] catalyzes trimethylsilylation of primary, secondary and tertiary alcohols as well as phenols, and the corresponding TMS-ethers were obtained in high yields and short reaction times at room temperature. While, under the same reaction conditions [Sn^IV(TPP)Cl₂] is less efficient to catalyze these reactions. One important feature of this catalyst is its ability in the chemoselective silylation of primary alcohols in the presence of secondary and tertiary alcohols and phenols. The catalyst was reused several times without loss of its catalytic activity.     

卟啉-蒽醌-苦味酸三联苯化合物的合成及其荧光性质初探

本文介绍了卟啉-蒽醌-苦味酸(P-AQ-T)三联体化合物的合成。以卤乙酰卤与1,5-二氨基蒽醌反应, 生成1,5-二(卤乙酰氨基)蒽醌, 再与卟啉和苦味酸联结, 得到P-AQ-T三联体。同时进行了荧光性质的比较。     

The incorporation of C_(60) in cavities of 5,10,15,20-tetra-4-oxy(2-stearic acid)phenyl porphyrin in LB film

The structure and properties of mixed monolayer or LB film of 5,10,15,20-tetra-4-oxy(2-stearic acid)phenyl porphyrin/C60 were studied. A isotherms and small angle X-ray diffraction (SAXD) results show that C60 molecules were incorporated into the cavities of por-phyrin molecules in mixed monolayer and LB film . UV-vis spectra of mixed LB films show that the absorption intensity of porphyrin varied compared with pure porphyrin film, probably arising from the interactions between C60 and porphyrin ring. C60 molecules in mixed systems are well-dispersed. The TPP(CO2H)/C60 mixed LB film is a kind of two-dimensional host-guest system.     

Biomimetic Decarboxylation of Carboxylic Acids with PhI（OAc）2 Catalyzed by Manganese Porphyrin [Mn（TPP）OAc]

Manganese（Ⅲ） meso-tetraphenylporphyrin acetate [Mn（TPP）OAc] served as an effective catalyst for the oxidative decarboxylation of carboxylic acids with （diacetoxyiodo）benzene [PhI（OAc）2] in CH2CI2-H2O（95：5, volume ratio）. The aryl substituted acetic acids are more reactive than the less electron rich linear carboxylic acids in the presence of catalyst Mn（TPP）OAc. In the former case, the formation of carbonyl products was complete within just a few minutes with 〉97% selectivities, and no further oxidation of the produced aldehydes was achieved under these catalytic conditions. This method provides a benign procedure owing to the utilization of low toxic（diacetoxyiodo） benzene, biologically relevant manganese porphyrins, and carboxylic acids.