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．     

四—（1—萘基）四苯并卟啉锰的合成和循环伏安特性研究

合成了氯化－四（１－萘基）四苯并卟啉锰配合物［ＴＮＴＢＰＭｎ（Ⅲ）Ｃｌ］。用元素分析、紫外可见光谱、红外光声光谱、质子核磁共振谱、摩尔电导进行了表征。用循环伏安法研究了ＴＮＴＢＰＭｎ（Ⅲ）Ｃｌ的电化学性质。结果表明，锰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－０．５２５Ｖ，卟啉环还原的半波电位为－１．７７０Ｖ。     

乙腈溶液中锇氮化合物电化学诱导桥氮偶联过程的原位FTIR反射光谱

采用原位红反射光谱（ｉｎ－ｓｉｔｕ－ＦＴＩＲＳ）结合紫外可见光谱（ＵＶ／Ｖｉｓ）和电化学徨伏安技术（ＣＶ）,研究了「Ｏｓ＾Ⅵ（Ｎ）（ＮＨ３）４」（ＣＦ３ＳＯ３）３的电化学诱导桥氮偶联过程。首次在Ｐｔ电极上检测到桥氮混合价锇物中「Ｏｓ－Ｎ≡Ｎ－ｏＳ」及其随电位的变化过程。在约２ｍ ｍｏｌ／Ｌ「Ｏｓ＾Ⅵ（Ｎ）（ＮＨ）」（ＣＦ要的乙腈溶液中,选取０．４－－１．０Ｖ电位区间１００ｍＶ／ｓ扫描速度,对Ｐｔ或     

氧化铁超微粒光电化学及光谱电化学研究

用拉曼光谱、光电流、紫外－可见反射谱等技术研究了附着在铂片表面的α－Ｆｅ２Ｏ３微粒。拉曼光谱的蓝移现象说明５０ｎｍ粒径的粒子较块体材料有尺寸量子化效应。随着电极电势的变化，光电流增加时，ＵＶ－ＶＩＳ反射率相对变化量减少；光电流减少，ＵＶ－ＶＩＳ反射率相对变化量则增大，说明电极电势不仅影响溶液氧化－还原对的氧化还原趋势，而且还影响微粒表面的光吸收。     

四（对—硝基）苯基卟啉合钴,锰,铁,锌配合物电化学和光谱电化 …

应用循环伏安法，现场紫外可见光谱电化学方法及现场ＦＴ－ＩＲ光谱电化学方法研究了标题配合物不同氧化状态的电位及光谱特征，指认了各步电极反应发生的点位，研究了硝基对不同氧化态金属卟啉电学性质，光谱性质的影响。     

含生色基团烯类单体及其聚合物——N－丙烯酰基吩■嗪及其聚合物的合成和其荧光性质

含生色基团烯类单体及其聚合物——Ｎ－丙烯酰基吩嗪及其聚合物的合成和其荧光性质＊于淑艳姚光庆李福绵（北京大学化学系北京１００８７１）关键词Ｎ－丙烯酰基吩嗪,紫外－可见光谱,荧光光谱,“结构自猝灭”效应,Ｓｔｅｒｎ－Ｖｏｌｍｅｒ常数,荧光寿命我们曾报...     

可溶性聚对苯乙炔的合成及其电致发光性能

采用紫外－可见光谱跟踪用直接聚合法制备可溶性的聚对苯乙炔衍生物的反应过程,结果表明反应仍然经历了生成前聚物的过程。控制反应条件使聚合反应首先生成前聚物,在前聚物烯化反应阶段加入起增溶作用的长链醇,得到了具有良好的溶解性的、主链中含非共轭链段的聚对苯乙炔衍生物。用该聚合物制备的电致发光器件,在５－６Ｖ电压驱动下发光,发光峰位于５８０ｎｍ左右。     

2,6—双（1′—苯基—3′—甲基—5′—氧代—4′—甲酰吡唑）吡啶稀土配合物的合成

在乙醇－水溶液中合成了１４种２，６－双（１′－苯基－３′－甲基－５′－氧代－４′－甲酰吡啶）吡啶稀土配合物，元素分析确定其化学组成的ＲＥ２Ｌ３．ｎＨ２Ｏ并用紫外可见光谱、红外光谱，核磁共振谱，热分析，荧光光谱，摩尔电导等进行了表征。     

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ｍｖ＾２＋反应，生成较稳定的ｍｖ＾＋。在Ｍｎ（Ⅲ）ＴＣＭＰＰ－ＭＶ＾２＋／ＣＨ３     

一个新型钌(II)配合物对F－的双重光谱识别

采用紫外-可见光谱和荧光光谱滴定方法研究了钌(II)配合物[Ru(bpy)(H2iip)2](ClO4)2 [bpy＝2,2’-联吡啶, H2iip＝2-吲哚基-咪唑并[4,5-f][1,10]-邻菲罗啉]在DMSO溶液中对卤素离子的识别性质. 结果表明该配合物能比色和荧光双重光谱高选择性识别F－.     

Unprecedented Charge‐Transfer Complex of Fused Diporphyrin as Near‐Infrared Absorption‐Induced High‐Aspect‐Ratio Nanorods

Charge‐transfer (CT) complexes of near‐infrared absorbing systems have been unknown until now. Consequently, structural similarities between donor and acceptor are rather important to achieve this phenomenon. Herein, we report electron donors such as non‐fused diporphyrin‐anthracene (DP), zinc diporphyrin‐anthracene (ZnDP) and fused zinc diporphyrin‐anthracene (FZnDP) in which FZnDP absorbs in NIR region and permits a CT complex with the electron acceptor, perylene diimide (PDI ) in CHCl₃ exclusively. UV/Vis‐NIR absorption, ¹H NMR, NOESY and powder X‐ray diffraction analysis demonstrated that the CT complex formation occurs by π–π stacking between perylene units in FZnDP and PDI upon mixing together in a 1:1 molar concentration in CHCl₃, unlike non‐fused ZnDP and DP. TEM and AFM images revealed that the CT complex initially forms nanospheres leading to nanorods by diffusion of CH₃OH vapors into the CHCl₃ solution of FZnDP/PDI (1:1 molar ratio). Therefore, these CT nanorods could lead to significant advances in optical, biological and ferroelectric applications.     

Analytical application of the poly(1H-1,2,4-triazole-3-thiol) modified gold electrode for high-sensitive voltammetric determination of catechol in tap and lake water samples

ABSTRACT

In this work, a simple, sensitive and rapid method for the determination of trace amounts of catechol (CT) in aqueous media has been suggested. For this purpose, poly(1H-1,2,4-triazole-3-thiol) film was electrochemically deposited successfully at the gold electrode (Au/T3T). The electrochemical behaviour of CT was studied on the Au/T3T electrode by the cyclic voltammetry and differential pulse voltammetry techniques. The anodic peak current value and the concentration of CT showed a good linear relationship in the range of 0.015–2.8 µM. The limit of detection was found as 1.88 nM (S/N = 3). Besides, the reproducibility, repeatability, stability and interference measurements were also assayed. This sensor was applied successfully for the detection of CT in synthetic and real samples.     

Structure,cyclic voltammetry and DNA-binding properties of the bis(pyridine)bis(sparfloxacinato)nickel(II) complex

The neutral mononuclear nickel(II) complex with the quinolone third-generation antibacterial drug sparfloxacin in the presence of the nitrogen-donor heterocyclic ligand pyridine has been synthesized and characterized. Sparfloxacin is deprotonated acting as a bidentate ligand coordinated to the Ni(II) ion through the ketone oxygen and a carboxylato oxygen. The crystal structure of bis(sparfloxacinato)bis(pyridine)nickel(II), 1, has been determined with X-ray crystallography. The cyclic voltammograms of the complex have been recorded in dmso solution and in 1/2 dmso/buffer (containing 150 mM NaCl and 15 mM trisodium citrate at pH 7.0) solution and the corresponding redox potentials have been estimated. The biological activity of the complex has been evaluated by examining its ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies and cyclic voltammetry. UV study of the DNA-interaction of the complex has shown that it can bind to CT DNA and the DNA-binding constant has also been calculated. The cyclic voltammograms of the complex in the presence of CT DNA have shown that the complex can bind to CT DNA by the intercalative mode. Competitive study with ethidium bromide (EB) has shown that the complex can displace the DNA-bound EB indicating that the complex binds to DNA in strong competition with EB for the intercalative binding site.     

Hydrothermal Synthesis of Monodispersed BaGdF5:Yb/Er Nanoparticles for CT and MR Imaging

In this paper, we report the development of a facile one‐pot hydrothermal method for the controlled synthesis of monodispersed BaGdF₅ :Yb/Er nanoparticles for computed tomography (CT) and magnetic resonance (MR) imaging. The as‐prepared nanoparticles have uniform size with a diameter of 20–25 nm. MTT tests show that the cell viability surpasses 90% even with a concentration of nanoparticles of 500 µg/mL, suggesting that the as‐prepared BaGdF₅ :Yb/Er nanoparticles possess low toxicity. For both BaGdF₅ :Yb/Er nanoparticles and iopromide, the Hounsfield unit (HU) values increase with the their concentration. The slope of BaGdF₅ :Yb/Er nanoparticles is about 26.47, which is much higher than that of iopromide (16.98), indicating a better CT imaging effect. Interestingly, we find that the synthesized BaGdF₅ :Yb/Er nanoparticles exhibit paramagnetism. Our in vitro and in vivo imaging experiments demonstrate that the synthesized monodispersed BaGdF₅ :Yb/Er nanoparticles can serve as effective contrast agents for CT and MR imaging.     

Activity of α‐Chymotrypsin in Cationic and Nonionic Micellar Media: Ultraviolet and Fluorescence Spectroscopic Approach

α‐Chymotrypsin (α‐CT) activity was measured in aqueous buffer with the following alkyltriphenylphosphonium bromide surfactants in the series cetyl, tetradecyl, and dodecyl as a tail length. For the sake of comparison with mixed micellar investigation on activity of α‐CT, cationic cetyltriphenylphosphonium bromide (CTPB) and nonionic surfactant Triton X‐100, Brij‐56, Brij‐35, Tween 20, and Igepal Co‐210 have been used. The p‐nitrophenyl acetate (PNPA) hydrolysis rate was determined at the surfactant concentration of both cationic and mixed micellar systems by a UV–vis spectrophotometer. The catalytic reaction follows the Michaelis–Menten mechanism, and the catalytic efficiency (k_cat/K_M) was evaluated for both homogeneous and mixed‐micellar media. The maximum catalytic efficiency was observed at 5 mM concentration of CTPB, but the highest catalytic efficiency, 572 M^?1 s^?1, was measured in the presence of mixed micellar (7.5 mM CTPB + 2.5 mM Tween‐20). The fluorescence (FL) spectra showed the differences of α‐CT conformations in the presence of cationic surfactants. The FL results suggest that the influence of cationic surfactant on proteolysis arises from the interaction with the α‐CT. The binding constant, k_sv, of α‐CT with cationic aggregates was determined in the buffer using the Stern–Volmer equation by the fluorescence spectroscopic approach.     

花菁-脱氧核糖核酸的共振光散射光谱及其分析应用

研究了一种苯并噻唑阳离子花菁与脱氧核糖核酸(DNA)作用的共振光散射光谱,在pH 6.0的六次甲基四胺-HCl缓冲介质中,痕量DNA的加入使花菁在590nm的共振光散射强度显著增强。在最佳实验条件下,增强的共振光散射强度与DNA浓度具有良好的线性关系,据此建立了一种测定DNA的共振光散射光谱法。方法的线性范围为:小牛胸腺DNA(CT DNA),0～20μg/mL,鱼精子DNA(FS DNA),0～15μg/mL;检出限分别为0.005μg/mL和0.008μg/mL。该方法已用于合成样品中DNA的测定。     

Spectroscopic studies of interaction of Safranine T with nonionic micelles and mixed micelles

The visible spectra of Safranine T (ST) in micellar solution of Brij 58, Tween 20 and Tween 40 and mixed micellar solution of Brij 58/Tween 20 and Brij 58/Tween 40 indicate formation of 1:1 charge transfer (CT) complex between acceptor ST and donor nonionic micelles and mixed micelles. The experimental CT transition energies are well correlated (through Mulliken's equation) with the vertical ionization potential of the donors. The solvent parameters, i.e. the intramolecular charge transfer energy ET(30) have been determined from the Stokes spectral shift. Variations of ionization potential and micropolarity in the mixed micellar region have been investigated as a function of surfactant composition and the obtained results in mixed micellar medium has been compared to the normal micelles. The critical micelle concentration (CMC) values determined at various surfactant compositions are lower than the ideal values indicating a synergistic interaction. The interaction parameter (beta) and micellar stability has been calculated using regular solution theory.     

Energies of Charge Transfer for the Supramolecular Complexes of [60]- and [70]Fullerenes with a Series of meso-Tetraphenylporphyrins in the Solution State

Supramolecular complexes of [60]- and [70]fullerenes with various meso-tetraphenylporphyrins in toluene solutions have been studied by electronic absorption spectroscopy. Charge transfer (CT) absorption bands are observed in the visible region. Vertical ionization potentials (I _D ^V) of the meso-tetraphenylporphyrins are reported from a study of EDA interaction of these porphyrins with a number of electron acceptors like o-chloranil, p-chloranil, 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and vitamin K. The dependence of the CT transition energy on the donor ionization potential has been utilized to estimate the vertical electron affinities (E _A ^V) of [60]- and [70]fullerenes in solution. The value of E _A ^V for [60]fullerene is found to be 0.10 eV lower in magnitude than that of [70]fullerene. We have extracted degrees of CT, and oscillator and transition dipole strengths of the fullerenes/meso-tetraphenylporphyrins complexes. The experimental results show that the CT complexes studied here have a neutral character in their ground states. Electronic coupling elements have been determined for fullerene/meso-tetraphenylporphyrin complexes. Values of the solvent reorganization energy indicate that the electron transfer process takes place at a faster rate in the case of [70]fullerene/meso-tetraphenylporphyrin complexes.     

Effect of ethanol on micellization and on decarboxylation of 6-nitrobenzisoxazole-3-carboxylate in aqueous cationic micelles

The effects of ethanol on the critical micellar concentration (cmc) and the rates of decarboxylation of 6-nitrobenzisoxazole-3-carboxylate (6-NBIC) have been investigated in aqueous cationic surfactants of the cetyltrialkylammonium family with bromide [CT(R)ABr], chloride [CT(R)ACl], and nitrate [CT(R)ANO3] counterions, and methyl (CTAX), n-propyl (CTPAX), and n-butyl (CTBAX) as the head group alkyl moieties. Effects upon cmc and reactivity are similar, featuring a break at the ethanol mole fraction, x(EtOH), of ca. 0.055; these effects have been related to changes in solvent structure, with formation of a clathrate at x(EtOH) = 0.055. Rate data in CTBABr were further investigated and fitting of raw kinetic data to the pseudophase model is possible up to x(EtOH) = 0.1, showing an unexpected decrease of rate constant values in the micellar pseudophase, kM', as ethanol content increases: a significant variation of micellar ionization degree could account for this kinetic effect.     

Resonance Rayleigh-scattering method for the determination of proteins with some monoazo dyes of chromotropic acid.

In a weak acid medium, protein reacts with a monoazo dye of chromotropic acid, such as Chromazol KS (CALKS), Acid Chrome Dark Blue (ACDB), Chrome Blue SE (CBSE), Acid Chrome Blue K (ACBK), Chlorophosphonazo I (CPAI), Arsennazo I (AAI) and Chromotrope 2R (CT2R), to form a combination product. This results in a significant enhancement of the resonance Rayleigh-scattering (RRS) intensity, and the corresponding RRS spectrum appears. The characteristics of the RRS spectra of the combination products and the optimum conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of protein in a certain range. The RRS methods have high sensitivity for the determination of protein, the detection limits for bovine serum albumin (BSA) are 10.0 - 30.2 ng/ml, and the sensitivity order is CALKS > AAI = CPAI > ACBK = CT2R > ACDB > CBSE. The selectivity for CALKS has been examined, and the method was applied to the determination of a microg amount of protein in a synthetic sample with satisfactory results.