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1.
MnTFPPCl模拟体系催化环己烯氧化反应性能研究 总被引:5,自引:0,他引:5
研究了高氟代金属卟啉MnTFPPCl催化环己烯氧化反应的催化活性,探索了反应体系中不同单氧原子给体对催化反应的影响。结果表明,MnTFPP-Cl/NaOCl体系有较好的催化转移氧能力。主要以PhIO为氧化剂,考察了轴向配体,溶剂等对MnTFPPCl/PhIO模拟体系的影响。 相似文献
2.
以三电极电池系统在不同电位下的在位测量测得四磺基苯基卟啉钠水溶液(浓度为5×10^-5mol/L)的表面增强拉曼谱。结果表明,在接近第一还原态电位处对吸附分子活化后,可得到较大倍数的增强信号(10^7数量级)。对照简正坐标计量结果,发现与N原子有关的振动模式有较大的增强,在此基础上提出了增强机理。 相似文献
3.
Ilaria Giuseppina Occhiuto Roberto Zagami Mariachiara Trapani Maria Angela Castriciano Andrea Romeo Luigi Mons Scolaro 《Molecules (Basel, Switzerland)》2020,25(23)
Under mild acidic conditions, various metal derivatives of tetrakis(4-N-methylpyridinium)porphyrin (gold(III), AuT4; cobalt(III), CoT4; manganese(III), MnT4 and zinc(II), ZnT4) catalytically promote the supramolecular assembling process of the diacid 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H2TPPS4) into J-aggregates. The aggregation kinetics have been treated according to a well-established model that involves the initial formation of a critical nucleus containing m porphyrin units, followed by autocatalytic growth, in which the rate evolves as a power of time. An analysis of the extinction time traces allows to obtain the rate constants for the auto-catalyzed pathway, kc, and the number of porphyrins involved in the initial seeding. The aggregation kinetics have been investigated at fixed H2TPPS4 concentration as a function of the added metal derivatives MT4. The derived rate constants, kc, obey a rate law that is first order in [MT4] and depend on the specific nature of the catalyst in the order AuT4 > CoT4 > MnT4 > ZnT4. Both resonance light scattering (RLS) intensity and extinction in the aggregated samples increase on increasing [MT4]. With the exception of AuT4, the final aggregated samples obtained at the highest catalyst concentration exhibit a negative Cotton effect in the J-band region, evidencing the occurrence of spontaneous symmetry breaking. The role of the nature of the metal derivative in terms of overall charge and presence of axial groups will be discussed. 相似文献
4.
利用LB (Langmuir-Blodgett)技术将含不同链长的卟啉化合物(C4Py, C6Py和C8Py)单层膜转移到ITO (indium-tin oxide)导电玻璃上, 发现其具有良好的光电转换性质. 卟啉化合物修饰后的紫外吸收光谱与光电流工作谱重叠, 表明卟啉化合物起到了敏化光电流产生的效果; 而且电子给体、电子受体和偏压对其敏化效果的实验结果表明: 光诱导电子转移是产生光电响应的主要原因. 而且, 这三个卟啉化合物的光电响应性质与碳链长度相关, 其中含有六个碳链的C6Py表现出最佳的光电转化效果. 相似文献
5.
本文以热处理方法制得的四苯基钴卟啉化学修饰电极为换能器,制备了一种新型葡萄糖酶电极。该传感器的使用寿命几乎不受测量次数的影响,抗干扰能力强,葡萄糖浓度在9.0×10~(-5)~1.3×10~(-3)mol/L范围内有线性响应,响应时间3s。 相似文献
6.
合成了一种5-氟尿嘧啶修饰的自由卟啉(5-[2-(5-氟尿嘧啶-3-基)乙氧基苯基]-10,15,20-三(4-甲氧基苯基)卟啉)及其2种金属卟啉配合物:5-[2-(5-氟尿嘧啶-3-基)乙氧基苯基]-10,15,20-三(4-甲氧基苯基)锰卟啉和5-[2-(5-氟尿嘧啶-3-基)乙氧基苯基]-10,15,20-三(4-甲氧基苯基)锌卟啉。 通过紫外可见光谱(UV-Vis)、红外光谱(IR)和核磁共振谱氢谱(1H NMR)对目标化合物进行了结构表征。 用噻唑蓝法(MTT法)测定了自由卟啉、锰卟啉及锌卟啉分别对肺腺癌细胞株A549、肝癌细胞株Bel7402和人结肠癌细胞株HCT-8的抑制活性。 其中,锰卟啉对人结肠癌细胞株HCT-8的半抑制浓度为IC50为17.8 mg/L,具有一定的细胞毒作用。 相似文献
7.
Sanyo Hamai Tomoko Ohshida 《Journal of inclusion phenomena and macrocyclic chemistry》2004,50(3-4):209-217
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. 相似文献
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10.
Determination of Nitrite by a Modified Electrode of Poly(1-Naphthylamine) Film Doped with Dawson-Type Heteropolyanions 总被引:1,自引:0,他引:1
The voltammetric behavior of the electrode modified with poly(1-naphthylamine) film doped with α-P2W18 heteropolyanions was investigated. The concentration of the modifier, the acidity of the medium and the scan range of potential
had obvious effects on the electrochemical characteristics of the electrode. The electrocatalytical characteristics of the
film electrode were studied by cyclic voltammetry and other methods. It is suggested that the electrocatalytic reaction of
nitrite is controlled by its diffusion. The applicability of the electrode was assessed by the determination of nitrite in
waste-water. Determination limit for nitrite was 5 × 10−7 mol.L−1.
Received August 23, 1999. Revision January 2, 2001 相似文献
11.
Active silica gel phase (I) was chemically modified to the corresponding amino- (SiNH2) and chloro- (SiCl) derivatives via silylation reactions. These were used to synthesize two newly modified silica gel phases (II, III) by direct chemical reaction with 2-hydroxynaphthaldehyde (2-HNA). The surface coverage values are 370, 432µmolg–1 and 320, 355µmolg–1 for (II) and (III), on the basis of thermal desorption and metal probe testing method, respectively. The metal sorption properties of silica gel phases (II, III) were studied and compared with active silica gel phase (I). The maximum determined metal capacity values were found to be 10–110, 20–290 and 20–370µmolg–1 for phases I, II and III, respectively. The distribution coefficient values (Kd) were also determined for a series of metal ions, and the results showed that the two new chemically modified phases (II and III) were highly selective for Cu2+, Zn2+, Cd2+, Hg2+ and Pb2+. The potential applications of silica gel phases (II, III) as solid phase extractors for the same five metal ions spiked in drinking tap water (1.000µgmL–1) were found to give percentage recovery values in the range of 90.2–96.3±4.1–6.3%, while pre-concentration of the same five metal ions spiked in drinking tap water (50.0ngmL–1) was successfully accomplished with a percentage recovery range of 92.6–95.8±4.8–5.7%.Received December 16, 2002; accepted May 14, 2003
published online September 1, 2003 相似文献
12.
Martin Lehmann Anastasios I. Zouboulis Kostas A. Matis Andreas Grohmann 《Mikrochimica acta》2005,151(3-4):269-275
In the course of researching methods of sampling and monitoring toxic metals (as arsenic ions) in water and wastewaters, we
selected the use of sorption for in-depth examination. Among other things, sorption modelling was investigated by the mechanism
of surface complexation in order to describe the process or even predict the outcome for the expected rate, and in general,
to develop this detection technique for pollutants. This investigation will include the application of goethite mineral as
the suitable metal ion sorbent and the use of appropriate computer software. The relative thermodynamic aqueous speciation
of the solution, in similar experimental conditions, was also studied. 相似文献
13.
四(对—羟基苯基)卟啉过渡金属配合物的合成 总被引:15,自引:0,他引:15
四(对-羟基苯基)卟啉过渡金属配合物的合成师同顺*柳巍刘国发王杏乔王世颖(吉林大学化学系长春130023)关键词卟啉,过渡金属配合物,合成1997-10-17收稿,1998-03-20修回国家自然科学基金会资助四(对-羟基苯基)卟啉(H2THPP)可... 相似文献
14.
The incorporation of metal ions into 5,10,15,20-tetrakis(4-N-methylpyridyl)porphine (TMPYP) were significantly accelerated
by 5-sulfo-8-quinolinol (SQN). The formation of Ni–TMPYP was completed within 5 min at 100 °C. Based on the comparison of
the acceleration effect of SQN with 8-quinolinol (QN), it was deduced that the acceleration of the incorporation reaction
is mainly due to the enhancement of the formation of the outer-sphere associate of Ni(II)–SQN complex with TMPYP, in which
the association is enhanced by both electrostatic and hydrophobic interactions between TMPYP and Ni(II)–SQN. This finding
was applied to the spectrophotometric determination of Ni(II). 相似文献
15.
meso-四(对-磺酸基苯基)卟啉对麦芽糖的分子识别高爽,王杏乔,于连香,曹锡章(吉林大学化学系,长春,130023)关键词卟啉,麦芽糖,分子识别分子识别在生物和生命活动中起着重要作用。近年来,以卟啉及其配合物为接受体对生物分子的人工分子识别研究日趋... 相似文献
16.
单链四苯酚基卟啉在CTAB胶束微环境中的去质子化现象 总被引:4,自引:1,他引:4
叶绿素分子的光能转化功能的实现与其聚集状态、所处微环境性质及条件密切相关[1,2].如何设计控制叶琳类分子在膜介质中的增溶位置,对于研究叶琳在膜体系中的跨膜电子传递、光能转化过程具有重要意义.本文研究了长链双亲卟啉──单链四苯酚基叶琳THPPH2在CTAB胶束中的去质子化,该过程能控制叶琳环在胶束中的增溶位置,使其由内核转移到胶束表面.1实验部分1·1仪器和测试条件岛津UV-240型紫外可见光谱仪(带有恒温夹套),狭缝宽2nm,石英池厚1cm,所用试剂皆为分析纯.UV光谱测试均在恒温条件下进行.1.2溶液的配制含一个十六… 相似文献
17.
WeiMinSHI JianWU YiFengWU KaiXianQIAN 《中国化学快报》2004,15(12):1427-1429
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. 相似文献
18.
The behaviour of solutions containing 7 metals in trace range (pH=2) prepared in borosilicate glass and polyethylene containers and transferred into commercial polyethylene–polypropylene and home-made quartz autosampler cups for measurements were studied using graphite furnace atomic absorption spectrometry. The different interactions between metal solution and vessel material were observed for the metals studied. The most significant losses of chromium and nickel occurred on a polyethylene surface, while the highest absorbance signals were registered from quartz containers. Higher absorbance signals from quartz containers were also obtained for cadmium and copper solutions. Contrary to these results, the absorbance signals for lead solutions were lowest when measured from quartz vessels. The container material had no influence on the analytical signals of cobalt and manganese.Received January 15, 2003; accepted April 15, 2003
published online August 22, 2003 相似文献
19.
5,10,15,20-四(2-噻吩基)金属卟啉修饰TiO2光催化剂的制备及光催化性能 总被引:1,自引:0,他引:1
合成了5,10,15,20-四(2-噻吩基)卟啉(H2TTP)及它的钴铜锌三种金属卟啉, 并用上述三种金属卟啉分别敏化锐钛矿型的二氧化钛, 制备了CoTTP-TiO2, ZnTTP-TiO2, CuTTP-TiO2三种光催化剂, 对这三种光催化剂进行了扫描电镜(SEM)、X射线光电子能谱(XPS)、紫外-可见漫反射光谱(UV-vis)、红外光谱(IR)的表征. 在300 W汞灯和400 W金卤灯照射下, 制备的光催化剂对4-硝基苯酚溶液的降解表现出比未修饰二氧化钛高的催化效率, 光催化降解反应符合反应一级动力学方程. 相似文献
20.
In the last decades, researchers have realised that the impact of trace elements (TE) in environmental solid substrates on
ecological systems and biota cannot be ascertained appropriately by means of total metal content measurements. Assessment
of TE chemical forms, types of binding and reactivity of their associations with particulate forms has, thus, been commonly
performed via batch-wise equilibrium-based sequential extraction fractionation methods able to discern TE bound to different
soil-phase compartments.
In this paper, novel analytical strategies for monitoring the mobility, bioavailability and the eventual impact of anthropogenic
TE in environmental solids are addressed. The potential of passive dosimeters based on microdialysis sampling for on-site,
real-time monitoring of chemical contaminants in pore soil solution is thoroughly discussed and critically compared with active
microsamplers. Recent miniaturised configurations designed for following the fate of target pollutants and the on-going chemical
changes occurring at local soil sites, e.g., the rhizosphere environment, at high temporal resolution are also presented in
detail.
Kinetic information on the lability of the various TE forms associated to soil phases under simulated environmental changing
conditions – that yield improved knowledge on short-term hazards of TE for the environment – can be obtained in a fully automated
mode by means of flow-through microcolumn fractionation procedures. The use of sequential injection analysis, in terms of
the implementation of on-line dynamic fractionation, is described and illustrated via selected examples comprising the well-accepted
three-step SM&T sequential fractionation, protocol. 相似文献