meso-四-(2-噻吩基)铜卟啉-环糊精超分子体系的光谱学研究

以紫外可见分光光度法和荧光光谱法研究了非水溶性meso-四-（2-噻吩基）铜卟啉（简称Cu—TTP）与四种环糊精α—CD、β—CD、γ—CD、TM—β—CD相互作用形成的超分子体系，结果表明Cu-TTP与TM-β-CD形成了1：2的包结物，而与其它三种环糊精主要形成1：1的包结物。在α—CD、β—CD、γ-CD三种母体环糊精中，α—CD与Cu—TTP的包结常数最大；β-CD与其衍生物TM-β-CD相比，TM-β-CD与Cu—TTP的包结常数较大。本文对四种环糊精和Cu-TTP的包结机理作了初步探讨。为铜卟啉和环糊精的相互作用及其超分子体系的研究提供了基础。     

Study on the supramolecular system of meso-tetrakis (4-sulfonatophenyl) porphyrin and cyclodextrins by spectroscopy

The ability of beta-cyclodextrin (beta-CD), sulfurbutylether-beta-CD (SBE-beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD) to break the aggregate of the meso-Tetrakis (4-sulfonatophenyl) porphyrin (TPPS4) and to form 2:1 inclusion complexes has been studied by adsorption and fluorescence spectroscopy. The formation constants are calculated, respectively by fluoremetry, from which the inclusion capacity of different CDs is compared and the inclusion mechanism of charged-beta-CD (SBE-beta-CD) is quite different from that of parent beta-CD. At lower pH, the complexation between HP-beta-CD and H2TPPS(2+)4 (the form of the diprotonated TPPS4) hampers the continuous protonation of the pyrrole nitrogen of TPPS4 and the hydrophobic cavity may prefer to bind an apolar neutral porphyrin molecule. 1HNMR data support the inclusion conformation of the porphyrin-cyclodextrin supramolecular system, indicating the interaction of meso-phenyl groups of TPPS4 with the cavity of CDs. For this host-guest inclusion model, cyclodextrin, being regarded as the protein component, which acts as a carrier enveloping the active site of heme prosthetic group within its hydrophobic environment, provides a protective sheath for porphyrin, creating artificial analogues of heme-containing proteins. However, the TPPS4, encapsulated within this saccharide-coated barrier, its physico-chemical, photophysical and photochemical properties changed strongly.     

Meso-四(对羟基苯基)卟啉及其金属配合物的合成与表征

以丙酸为溶剂，用吡咯和对羟基苯甲醛直接合成了Meso-四（对羟基苯基）卟啉，探讨了溶剂丙酸和无水乙醇的用量对反应产率的影响；利用液相法合成了Mesc〉四（对羟基苯基）卟啉与Fe^3＋，Mn^2＋，Co^2＋，Ni^2＋，Cu^2＋和Zn^2＋ 6种金属离子形成的配合物，探讨了Meso-（对羟基苯基）卟啉与金属盐用量的比例对产率的影响；利用UV-Vis和MS对合成的物质进行表征．     

Spectroscopic study and antioxidant properties of the inclusion complexes of rosmarinic acid with natural and derivative cyclodextrins

Measurement of total antioxidant activity/capacity of polyphenols in various solvent media necessitates the use of cyclodextrins to solubilize lipophilic antioxidants of poor aqueous solubility. The inclusion complexes of the slightly water soluble antioxidant, rosmarinic acid (RA), with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), 2-hydroxyethyl-β-cyclodextrin (HE-β-CD), and methyl-β-cyclodextrin (M-β-CD) were investigated for the first time. The effect of cyclodextrins (CDs) on the spectral features of RA was measured in aqueous medium using UV-vis and steady-state fluorescence techniques by varying the concentrations of CDs. The molar stoichiometry of RA-CD inclusion complexes was verified as 1:1, and the formation constants of the complexes were determined from Benesi-Hildebrand equation using fluorescence spectroscopic data. Among the CDs, maximum inclusion ability was measured in the case of M-β-CD followed by HP-β-CD, HE-β-CD, β-CD and α-CD. Solid inclusion complexes were prepared by freeze drying, and their functional groups were analyzed by IR spectroscopy. Antioxidant capacity of CD-complexed rosmarinic acid was measured to be higher than that of the lone hydroxycinnamic acid by the CUPric Reducing Antioxidant Capacity (CUPRAC) method. The mechanism of the TAC increase was interpreted as the stabilization of the 1-e oxidized o-catechol moiety of RA by enhanced intramolecular H-bonding in a hydrophobic environment provided by CDs, mostly by M-β-CD.     

Synthesis of 2,5 -Bis(4-methyl-2-thienyl)thiophene and 2,5-Bis(4-methyl-2-thienyl)pyrrole

Syntheses of 2,5-bis(4-methyl-2-thienyl)thiophene 3 and 2,5-bis(4-methyl-2-thienyl)pyrrole 4 are described. The key step involves Stetter reaction between 4-methyl-2-thiophenecarboxaldehyde and divinyl sulfone. Cyclizaton of the resulting 1,4-bis-(4-methyl-2-thienyl)-1,4-butanedione 2 with Lawesson's reagent gives 2,5-bis(4-methyl-2-thienyl)thiophene 3, whereas condensation with ammonium acetate provides the 2,5-bis(4-methyl-2-thienyl)pyrrole 4.     

水溶性四(p-磺酸钠苯基)金属卟啉配合物的合成、光谱性质及催化三氯苯酚的氧化脱氯反应

通过四苯基卟啉(H2TPP)和浓硫酸发生磺化反应及其金属化, 控制反应体系pH并利用透析法纯化, 高效合成了水溶性四(对磺酸钠苯基)卟啉(H2TPPS)及其金属配合物(FeTPPS和ZnTPPS); 采用UV-Vis、荧光、1H NMR和FTIR等光谱手段表征及研究了水溶性卟啉的结构及性质. 结果表明, 磺酸根离子的存在增强了卟啉分子间的π-π作用, 从而使H2TPPS及其金属配合物的分子间聚合作用增强. 研究了FeTPPS对2,4,6-三氯苯酚(TCP)催化氧化脱氯反应, 结果表明, FeTPPS/H2O2催化体系对TCP具备很好的催化氧化脱氯性能, 2,6-二氯对苯醌的转化数达到了766.     

Liquid chromatography of cyclodextrins with indirect photometric detection of phenolphthalein inclusion complexes

Summary - and -cyclodextrin (CD) separated by liquid chromatography have been indirectly detected by depression of the background absorbance at a visible wavelength by means of inclusion complexation with phenolphthalein. The background signal was generated by phenolphthalein in an alkaline medium. Octadecyl-bonded poly(vinylalcohol) packings were employed as the stationary phase, which allowed the use of alkaline mobile phases, and eliminated post column mixing of reagents. The detection limits for - and -CD were 0.1–0.5 M at a signal to noise ratio of 3. -CD could not be measured by the present detection principle.     

Structural patterns in clathrates and crystalline complexes of zinc-tetra(4-chlorophenyl)porphyrin and zinc-tetra(4-fluorophenyl)porphyrin

Twelve new crystalline materials based on zinc-tetra(4-chlorophenyl)porphyrin (8 compounds) and zinc-tetra(4-fluorophenyl)prophyrin (4 compounds) building blocks have been prepared and characterized by X-ray diffraction analysis. Several different modes of guest solvent incorporation into the porphyrin lattice, including enclathration (of solvents of low polarity) and complex formation (with strong Lewis bases), and of intermolecular organization have been detected. Unique interporphyrin architectures, affected by directional Cl...Cl interactions, characterize most of the known solid structures of the chlorosubstituted materials. A small number of the latter, as well as the fluorosubstituted derivatives, exhibit interporphyrin arrangements of the type which are commonly observed in the clathrates of unsubstituted tetraphenylmetalloporphyrins. The pore structure of these compounds is affected to a large extent by the nature of the incorporated solvate and, consequently, the degree of coordination of the metal center. In crystals of four-coordinate porphyrins the solvent guest components are usually incorporated into channel-type cavities formed between columns and layers of densely stacked hosts. In five-coordinate and six-coordinate materials the guest sites coincide with the axial coordination sites of the porphyrin metal atoms. The latter structures reveal a tight fit between adjacent layers of the complexed entities, the axial ligands of one layer being incorporated into localized interporphyrin cavities of another layer. Dipolar forces play also an important role in the interporphyrin organization.Supplementary Data relating to this article have been deposited with the British Library as supplementary publication No. SUP 82183 (97 pages).     

Convenient synthesis of Pt(0) olefin complexes by colorimetric reduction of Pt(II) complexes with SmI2

Homoleptic olefin platinum(0) complexes, Pt(C₇H₁₀)₃ and Pt(cod)₂, were synthesized by the colorimetric reduction of platinum(II) complexes with SmI₂ in the presence of 2-norbornene or COD. This is a practically more convenient method for the synthesis of the Pt(0) complexes than the literature method employing Li₂(cot).     

Palladium(II) complexes with R2edda-derived ligands

Four palladium(II) complexes with R₂edda ligands, dichlorido(O,O′-dialkylethylenediamine-N,N′-diacetate)palladium(II) monohydrates, [PdCl₂(R₂edda)]?H₂O, R = Me, Et, n-Pr, i-Bu, and the new ligand precursor i-Bu₂edda?2HCl?H₂O, O,O′-diisobutylethylenediamine-N,N′-diacetate dihydrochloride monohydrate, were synthesized and characterized by IR, ¹H and ¹³C NMR spectroscopy, and elemental analysis. DFT calculations were performed for the palladium(II) complexes and a high possibility for isomer formation due to stereogenic N ligand atoms was confirmed. Moreover, DFT simulations revealed energetic profile of isomer formation. Computational outcomes are in agreement with spectroscopic instrumental findings, both strongly indicating a non-stereoselective reaction between selected esters and K₂[PdCl₄], forming isomers.     

Synthesis,structural characterization and catalytic potential of oxidovanadium(IV) and dioxidovanadium(V) complexes with thiazole-derived NNN-donor ligand

Reaction between the tridentate NNN donor ligand, (E)-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)benzo[d]thiazole (HL), and V₂O₅ in ethanol gave a new vanadium(V) complex, [VO₂L] (1), while the similar reaction by using [V^IVO(acac)₂] as the metal source gave two different types of crystals related to compounds [VO₂L] (1) and [V^IVO(acac)L] (2). The molecular structures of the complexes were determined by single-crystal X-ray diffraction and spectroscopic characterization was carried out by means of FT-IR, UV–vis and NMR experiments as well as elemental analysis. The oxidovanadium(IV) and dioxidovanadium(V) species were used as catalyst precursors for olefin oxidation in the presence of hydrogen peroxide (H₂O₂) as an oxidant. Under similar experimental conditions, the presence of 1 resulted in higher oxidation conversion than 2.     

Studies on the effects of metal ions and counter anions on the aggregate behaviors of meso-tetrakis(p-sulfonatophenyl)porphyrin by absorption and fluorescence spectroscopy

The aggregation behaviors of meso-tetrakis(p-sulfonatophenyl)porphyrin (TPPS) in the function of metal ions and their counter anions (Cl(-), SO(4)(2-), and NO(3)(-)) were investigated by absorption, fluorescence spectroscopy and resonance scattering spectrum. It was shown that the TPPS J-aggregates could be effectively promoted by metal ions under lower ionic strength. Moreover, the prominent effects of counter ions (Cl(-), SO(4)(2-), and NO(3)(-)) on TPPS J- and/or H-aggregate formation at higher ionic strength were observed. These results suggested that the counter anions play a significant role in the formation of TPPS J- and/or H-aggregates and their conversion each other. Very interestingly, the absorption spectrum of metal ions investigated except for Co(2+) leaves a WINDOW from ca. 450 to 550nm centered at 490nm in which the absorption of Cu(2+) or Ni(2+) ions per se was very weak. The spectrum window might be really significant in avoiding possible spectrum interferences when porphyrins are chosen as spectrometric reagents for the determination of metal ions based on J-aggregation.     

Synthesis and structural characterization of ruthenium(II) and iron(II) complexes containing 1,2-di-(2-thienyl)-ethene derived ligands as chromophores

A new family of three-legged piano stool structured organometallic compounds containing the η⁵-cyclopentadienylruthenium(II)/iron(II) fragments {M(η⁵-C₅H₅) (DPPE)}⁺, {Ru(η⁵-C₅H₅)(PPh₃)₂}⁺ and {Ru(η⁵-C₅H₅)(TMEDA)}⁺ with coordinated thiophene based chromophores, namely 5-(2-thiophen-2-yl-vinyl)-thiophene-2-carbonitrile (L1) and 5-[2-(5-Nitro-thiophen-2-yl)-vinyl]-thiophene-2-carbonitrile (L2) has been synthesized and fully characterized by ¹H, ¹³C, ³¹P NMR, IR and UV-Vis spectroscopies. Also, electrochemical studies were carried out by cyclic voltammetry and all experimental data are interpreted and compared with related compounds under the scope of NLO properties. Compounds [Ru(η⁵-C₅H₅)(DPPE)(NC(C₄H₂S)C(H)C(H)(C₄H₃S))][CF₃SO₃] (1′Ru) [Fe(η⁵-C₅H₅)(DPPE)(NC(C₄H₂S)C(H)C(H)(C₄H₃S))] [PF₆] (1Fe) and [Ru(η⁵-C₅H₅)(DPPE)(NC(C₄H₂S)C(H)C(H)(C₄H₂S)NO₂)][CF₃SO₃] (4′Ru) were also crystallographically characterized.     

High-performance thin-layer chromatography of metal complexes ofmeso-tetrakis(p-tolyl)porphyrin on cellulose and silica gel

Summary The migration behavior of metal complexes ofmeso-tetrakis(p-tolyl)porphyrin (TTP) are studied in HPTLC systems with cellulose and silica gel thin-layers and various organic solvents of relatively low polarity. The mobility of the metal complex tends to increase in the following orders of its central-metal elements: on cellulose, Mg(II)<Zn(II)<V(IV)<(H)<Pd(II)< Ni(II)Cu(II); on silica gel, Mg(II)<V(IV)<Zn(II)= (H)<Ni(II)Pd(II)Cu(II). Recommendable phase system for the separation of metal-TTP complexes is a combination of silica gel thin-layer with a carbon disulfide-m-xylene mixture though the complexes of Ni, Cu and Pd are not completely resolved.     

Synthesis and cytotoxicity study of gold(III) porphyrin complexes and their derivative in breast cancer cells

Gold(III) [Au(III)] complexes exhibit potential anticancer activities. A series of Au(III) porphyrin complexes containing different meso-substituent groups (phenyl, methoxyphenyl, butyloxyphenyl, octyloxyphenyl, and decyloxyphenyl) was synthesized. The synthesized compounds were characterized using mass spectrometry, infrared spectroscopy, UV–visible and fluorescence spectroscopy, and electron paramagnetic resonance spectroscopy. Moreover, the in vitro cytotoxicity of these Au(III) porphyrin complexes was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide surrogate viability assay on an MCF7 human breast cancer cell line. The Au(III) complexes with 5,10,15,20-tetraphenylporphyrin (AuTPP) and 5,10,15,20-tetrakis(4-methyloxyphenyl)porphyrin (AuTOMPP) demonstrated high anticancer activity with IC₅₀ values against MCF7 cells at 4.30 and 25.35 µM, respectively. The toxicity of the Au(III) porphyrin complexes against the LLC-MK2 rhesus monkey kidney epithelial cell line, a representative normal cell line, was investigated. All the tested Au(III) porphyrin complexes were non-cytotoxic in LLC-MK2 cells. For AuTPP, more than 80% LLC-MK2 cell viability was observed at concentrations lower than 5 μM.     

Inclusion Complexes of Cyclodextrins with Tetrakis(4-carboxyphenyl)porphyrin and Tetrakis(4-sulfonatophenyl)porphyrin in Aqueous Solutions

In neutral and alkaline solutions, tetrakis(4-carboxyphenyl)porphyrin (TCPP) and tetrakis(4-sulfonatophenyl)porphyrin (TSPP) form 1:1 and 2:1 host–guest inclusion complexes with -cyclodextrin (-CD), -cyclodextrin (-CD), and 6-deoxy-6-diethylamino--CD (DEA--CD), except for DEA--CD in alkaline solution. On the other hand, TCPP and TSPP form only 1:1 inclusion complexes with 6-deoxy-6-dihexylamino--CD (DHA--CD). The limited solubilities of DEA--CD in alkaline solution and DHA--CD are likely responsible for no observation of the 2:1 inclusion complex containing DEA--CD in alkaline solution and that containing DHA--CD. The equilibrium constants (Ks) of TCPP and TSPP for the formation of the inclusion complexes have been estimated from the absorption and/or fluorescence intensity changes in neutral and alkaline solutions. The K₂ values, which are the equilibrium constants for the formation of the 2:1 host–guest inclusion complex from the 1:1 inclusion complex, are about one tenth the corresponding K₁ values, except for the -CD–TSPP system in alkaline solution. In neutral solution, where DEA--CD and DHA--CD are in protonated forms, the electrostatic force operates between DEA--CD (DHA--CD) and TCPP (TSPP), leading to the greater K values than those in alkaline solution, where DEA--CD and DHA--CD exist as neutral species.     

活性艳红K-2G与环糊精相互作用的极谱伏安法研究

研究了单偶氮染料活性艳红K-2G的极谱伏安行为。实验表明：在底液为0．1mol／L的NaGl溶液中活性艳红K-2G有一稳定的、灵敏的还原峰,峰电位约为-0．78mV（vs．SEE）。用线性扫描二阶导数极谱法研究了活性艳红K-2G与不同环糊精的相互作用。采用“电流法”测定了包结常数,比较了不同类型环糊精的包结能力,初探了包结点的可能位置,并对其进行了理论分析。     

Interaction of monosulfonate tetraphenyl porphyrin (H2TPPS1) with plant-esterase: determination of the binding mechanism by spectroscopic methods

The interaction of monosulfonate tetraphenyl porphyrin (H(2)TPPS(1)) with plant-esterase was investigated using fluorescence and UV-vis absorption spectroscopy. Fluorescence quenching, from which the binding parameters were evaluated, revealed that the quenching of the esterase by H(2)TPPS(1) resulted from the formation of a dye-esterase complex. According to the modified Stern-Volmer equation, the effective quenching constants (K(a)) between H(2)TPPS(1) and plant-esterase at four different temperatures (297 K, 300 K, 303 K, and 306 K) were obtained to be 14.132×10(5), 5.734×10(5), 2.907×10(5), and 2.291×10(5) M(-1), respectively. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) for the reaction were calculated to be -181.67 kJ M(-1) and -0.49 kJ M(-1)K(-1), indicating that van der Waals force and hydrogen bonds were the dominant intermolecular force in stabilizing the complex. Site marker competitive experiments showed that the binding of H(2)TPPS(1) to plant-esterase primarily took place in the active site. The binding distance (r) was obtained to be 5.99 nm according to F?rster theory of non-radioactive energy transfer. The conformation of plant-esterase was investigated by synchronous fluorescence and UV-vis absorption spectroscopy, and the results confirmed some micro-environmental and conformational changes of plant-esterase molecules.     

Synthesis,characterization and thermal analysis of [Fe(N2H4)2(CH3COO)2]

[Fe(N₂H₄)₂(CH₃COO)₂] was synthesised and characterized for the first time by chemical analysis, magnetic measurements, electronic and IR spectral studies. Its thermal reactivity was ascertained by thermogravimetric (TG) and derivative thermogravimetric (DTG) techniques and it has been concluded that unlike some other metal carboxylate hydrazinates, it does not show any autocatalytic behaviour. The decomposition was also subjected to kinetic analysis using the equations of Coats-Redfern and Horowitz-Metzger by the method of weighted least-squares.     

meso-四(2-羟基-5-磺酸苯基)卟啉的合成及其酸碱平衡的研究

本文对 meso-四(2-H-5-SP)P 的提纯方法进行了改进,同时以光度法研究了该试剂在水溶液中的酸碱平衡、测得其 pKa_1、pKa_2、pKa_3、pKa_4分别为2.99,4.21,8.68,10.28。