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排序方式: 共有822条查询结果,搜索用时 234 毫秒
21.
The kinetics of oxidation of ascorbic acid in the presence of cobalt octa-4,5-carboxyphthalocyanine sodium salt (Teraphthal) was studied. A kinetic equation was obtained and a scheme of the process was proposed. According to the scheme, the first stage is the formation of a complex of the catalyst with dioxygen, and the limiting stage is the reaction of dioxygen with the ascorbate monoanion. The influence of the pH of the medium and the presence of a transport protein (albumin) on the state and catalytic activity of Teraphthal was studied. The involvement of hydrogen peroxide and oxygen-centered radicals in the catalytic oxidation of ascorbic acid was proved. 相似文献
22.
实验研究结果表明双核金属酞菁类化合物MPc-PcM(M=V、Cr、Mn、Fe、Co、Ni、Cu)是催化H_2S液相氧化反应的良好催化剂,且其催化活性顺序为Co>Ni>V>Fe>Cu>Cr>Mn.采用量子化学理论计算方法(INDO/S)分析了其前线分子轨道的构成特征,结果表明这几种MPc-PcM的LUMO轨道皆为有金属离子参与形成的π轨道,但HOMO轨道间的差异却很大.M=Co、Ni、Cu、Cr时,其HOMO为π轨道;而M=Fe、Mn时,其HOMO却为σ轨道.正是在前线分子轨道的轨道类型、共轭程度及金属轨道贡献三方面因素的协同作用下,才导致MPc-PcM的催化活性顺序并非按中心金属离子价电子层d电子数的递变而呈现出规律性的变化. 相似文献
23.
酞菁氧钛的合成及晶型转化 总被引:4,自引:0,他引:4
酞菁氧钛以联环己烷为溶剂,以邻苯二脂及四氯化钛直接反应生成。其优点是便于分离及纯化。同时对各晶型的获得及晶型间的相互转化进行了研究,并以X-射线粉末衍射及FT-IR进行了表征,并记录了不同晶型的酞菁氧钛在室温硫化硅橡胶中的吸收光谱。 相似文献
24.
Pd(OAc)2/FePc催化环己烯氧化合成环己酮的研究 总被引:6,自引:0,他引:6
考察了几种Fe-大环配合物与Pd(OAc)2组成的双组分催化体系,在乙腈酸性水溶液中环己烯经合成环己酮的催化活性,实验结果表明,其中以酞菁失(FePc)与Pd(OAc)2组成的催化体系活性最高,而FeTPPCl与Pd(OAc)2催化体系,虽然催化活性较高,但催化剂的稳定性较低,各种因素对Pd(OAc)2/FePc催化活催化影响的研究结果指出,在无水和酸存在的非水溶液中,Pd(OAc)2/FePc对 相似文献
25.
铁,钴,铜酞菁/Y型分子筛的制备,表征及催化苯酚羟化的研究 总被引:4,自引:0,他引:4
制备了铁,钴,铜酞菁/Y型发子筛,利用元素分析,IR、UV-Vis,TG、BET及XRD确定了分子筛笼中铁,钴,铜酞菁化合物的生成及其晶体结构,考察了实验参数对苯酚的转化率及产物选择性的影响。 相似文献
26.
Comparison of the photophysics of an aggregating and non-aggregating aluminium phthalocyanine system incorporated into unilamellar vesicles 总被引:2,自引:0,他引:2
The hydrophobic sensitizer, aluminium phthalocyanine chloride (AIPcCI), and the amphiphilic sensitizer, cis-disulphonated aluminium phthalocyanine (cis-AIPcS2), were incorporated into small unilamellar vesicles (SUVs) and large unilamellar vesicles (LUVs). AIPcCI exhibits aggregation, which increases with increasing sensitizer concentration, whereas cis-AlPcS2 is monomeric at all concentrations studied. Complex fluorescence decays are observed, showing decay time distributions which broaden with increasing phthalocyanine concentration. The phthalocyanine aggregate, although non-fluorescent, influences the overall photophysical behaviour of the phthalocyanine-vesicle system. The effect of aggregation on the resulting photophysics of phthalocyanines was investigated by comparing aggregated and non-aggregated phthalocyanine systems. The implications for photodynamic therapy (PDT) are briefly discussed. 相似文献
27.
Trapping Copper Phthalocyanine in a Silica Sono-Xerogel 总被引:1,自引:0,他引:1
R. Litrán E. Blanco M. Ramírez-del-solar L. Esquivias 《Journal of Sol-Gel Science and Technology》1997,8(1-3):985-990
A copper phthalocyanine (CuPc) has been encapsulated in silica. The trapping effects were studied comparing the UV-Vis absorption
spectra of some CuPc solutions and composites prepared under different conditions. The trapped organic molecules’ stability
was monitored during the gelation and drying processes. Leachability test have been carried out with the aim of checking the
trapping efficiency. Hydrolysis water of pH=2 and a molar ratioR
w
=6 mol acid H2O/mol TMOS leads to a higher CuPc stacking angle homogeneity. The increase of Pc induces a narrower mesopore distribution
and helps the stabilization of the composite. 相似文献
28.
The coordination of nitric oxide (NO) to cobalt(II) phthalocyanine (CoPc) in dimethyl sulphoxide (DMSO) has been studied. CoPc coordinates with NO in a 1:1 ratio, forming a CoPc(NO) species. The IR band observed at 1680 cm−1 is assigned to the coordinated NO. In the presence of excess NO, pseudo first order kinetics were followed. The observed rate constant, kf, was determined to be 15.0±0.3 dm−3 mol−1 s−1 and the equilibrium constant was K=5.4±0.4×104dm3 mol−1. Solution or adsorbed CoPc catalyses the reduction of NO. The products of reduction include NH3 and NH2OH. 相似文献
29.
Metal(II) tetranitro phthalocyanines of cobalt, nickel and copper are synthesized in pure state by a novel modified method. The complexes are characterized using elemental, electronic and IR spectral studies. Pure metal(II) tetra-amino phthalocyanines of cobalt, nickel and copper are synthesized by reducing the nitro groups of the above complexes using sodium sulphide. These complexes are also characterized by elemental, electronic, IR spectral and magnetic susceptibility measurements. The nature of the electrical conductivities of the above three metal(II) tetra-amino phthalocyanine derivatives are studied in the temperature range 303-473 K and the data are presented. Among the effect of various substituent groups on the electrical conducting property of phthalocyanine, amine group substituent on the peripheral benzene ring of the phthalocyanine molecule has been found to increase electrical conductivity to a greatest extent. These complexes showed about 105-106 times higher electrical conductivities compared to their parent phthalocyanine compounds. 相似文献
30.
A novel solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles (NanoCoPc) as ionophore was fabricated without any need of auxiliary materials (such as membrane matrix, plasticizer, and other additives). The electrode was prepared by simple drop-coating NanoCoPc colloid on the surface of a glassy carbon electrode. A smooth, bright and blue thin film was strongly attached on the surface of the glassy carbon electrode. The electrode showed high selectivity for ascorbic acid, as compared with many common anions. The influences of the amount of NanoCoPc at the electrode surface and pH on the response characteristics of the electrode were investigated. To overcome the instability of the formal potential of the coated wire electrode, a novel electrochemical pretreatment method was proposed for the potentiometric sensor based on redox mechanism. This resulting sensor demonstrates potentiometric response over a wide linear range of ascorbic acid concentration (5.5 × 10−7 to 5.5 × 10−2 M) with a fast response (<15 s), lower detection limit (ca. 1.0 × 10−7 M), and a long-term stability. Furthermore, microsensors based on different conductors (carbon fiber and Cu wire) were also successfully fabricated for the determination of practical samples. 相似文献