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制备了5,10,15,20-四(苯基)卟啉钴配合物(CoTPP), 并利用该配合物与氧化石墨烯(GO)的π?π堆积作用组装了CoTPP/GO电催化产氢复合材料. 研究发现, 当CoTPP与GO的质量比为1∶15时, 复合材料的性能最佳. 该材料的拉曼和扫描电子显微镜结果显示, 与GO相比, CoTPP/GO复合材料表面的无序程度增加, 形貌改变有利于促进反应体系的电荷迁移与分离; 交流阻抗测试结果显示, 阻抗值由GO的1180 Ω降低为CoTPP/GO材料的734 Ω; 电化学测试结果显示, 析氢起始过电位由-761 mV降低为-337 mV, 塔菲尔斜率由296 mV/dec 降低至174 mV/dec, 法拉第效率却由23%提高至87%. 加入二苯硫醚(SPh2)轴向配体后, CoTPP(SPh2)/GO材料的析氢起始过电位进一步降低至-235 mV, 塔菲尔斜率降低至163 mV/dec, 法拉第效率提高至94%. 研究结果表明, 通过氧化石墨烯与金属卟啉的非共价键自组装是构筑石墨烯基电催化产氢材料的一个有效途径. 相似文献
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非对称取代卟啉钴(Ⅱ)轴向配位反应的热力学研究 总被引:3,自引:2,他引:3
合成了非对称对位取代卟啉钴(Ⅱ)(5-(4-乙酰胺基苯基)-10,15,20-三(4-甲基苯基)卟啉钴(Ⅱ))用分光光度法测量了该体系与一系列含咪唑基配体(2-甲基咪唑(2-MeIm),N-甲基咪唑(N-MeIm)2-乙基-4-甲基咪唑(EMIm)克霉唑(GMZ)轴向配位反应的平衡常数,研究结果表明,配体的尺寸及取代基的位置将向轴向配合物的稳定性产物影响,其平衡常数呈现KGMZ〉KN-MeIm〉K 相似文献
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选择一种金属卟啉有机物(5-对-烷氧基苯基-10,15,20-三苯基卟啉羟基稀土化合物, HoOH)和4,4'-联吡啶(44BPY)作为自组装膜的基本构筑单元, 利用金属配位作用, 成功地将HoOH单分子膜组装到44BPY修饰的银表面. 采用紫外-可见吸收光谱、表面增强拉曼光谱研究了金属卟啉自组装膜的形成并且探索其结构和取向的变化. 结果表明, 底层的44BPY通过4位的N原子垂直吸附到银表面, 另一端的吡啶环上的N原子与HoOH的金属中心配位形成化学键. 从而在44BPY长轴向方向上将HoOH连接到44BPY自组装膜上, 并形成了新的交替膜. 之后, 底层的44BPY取向发生变化, 更向基底倾斜, 而上层的HoOH的分子平面则近乎平行于基底. 相似文献
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利用轴向配位作用将5,10,15-20-四苯基钴(Ⅱ)卟啉(CoTPP)固定在4-巯基吡啶自组装膜表面上,形成CoTPP单分子膜,通过组装金纳米粒子的方法,成功地获得了膜中CoTPP分子的喇曼光谱。研究结果表明,CoTPP分子是通过钴原子与氮原子之间的配位作用与巯基吡啶分子结合的,且其分子平面与基底表面近似平行。 相似文献
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合成了2种新型锌卟啉并与金属Mn构建配位聚合物(CPsx,x=1,2)。2种配位聚合物与锚定卟啉(ZnPA)通过金属-配体轴向配位自组装染料敏化太阳能电池(DSSC)。测试结果表明自组装电池具有较好的光电转换效率,特别是基于CPs2的装置具有较高的短路电流和转换效率。我们还对其光学、电化学及光电性能进行了研究,并通过透射电镜(TEM)对自组装体有效敏化在TiO_2电极上进行验证。 相似文献
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利用超高真空低温扫描隧道显微镜系统研究了meso-四对甲氧基苯基卟啉钴分子在Au(111)、Ag(111)和Cu(111)表面的吸附与自组装.该分子在金属表面可以形成两种组装结构A和B.在结构A中,分子间的相互作用主要为π-π堆叠,仅在Au(111)和Ag(111)表面被实验观察到;在结构B中,分子间的相互作用为氢键,仅在Ag(111)和Cu(111)表面被实验观察到.分子-衬底相互作用的差异所引起的分子吸附构象变化被认为是导致不同衬底上的分子形成不同组装结构的原因.研究发现在不同衬底上,分子形成自组装结构的行为存在明显差异.在相近覆盖度下,未参与组装的分子的比例在Cu(111)表面最高, Au(111)次之, Ag(111)最低.表面上参与形成两种组装结构的分子与未参与组装的分子的比例还可通过覆盖度和退火来进行调控. 相似文献
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铜卟啉-L-半胱氨酸自组装复合膜修饰电极的制备及电化学性能研究 总被引:4,自引:2,他引:2
利用电化学扫描法在L 半胱氨酸(Cys)自组装单分子膜修饰金电极表面现场制备了金属卟啉复合膜,对其进行SEM和ATR FTIR表征。修饰电极的支持电解质以及pH值对膜的稳定性和灵敏度有很大影响。铜卟啉 L Cys膜对H2O2具有良好的电催化还原特性,催化电流与H2O2浓度在1 0×10 6到3 0×10 5mol·L 1范围内线性关系,相关系数0 9995,检测限达1 0×10 7mol·L 1。 相似文献
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A one-dimensional chain coordination polymer [Co(II)(C6H5CH=CHCOOH)2(4,4′- bipy)(H2O)5]n has been synthesized with cinnamylic acid, 4,4′-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a = 1.1481(3), b = 1.1230(2), c = 1.1759(3) nm, β = 97.054(4)o, V = 1.5046(6) nm3, Mr= 617.50, Dc = 1.363 g/cm3, Z = 2, μ(MoKα) = 0.627 mm-1, F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(II) ions are linked together by one 4,4′-bipy, and the whole complex molecule adopts a one-dimensional chain structure. Each cobalt(II) ion is coordinated with two nitrogen atoms from two 4,4′-bipy molecules and four oxygen atoms from four water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were analyzed by combining with the crystal structure. 相似文献
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Ke Qiang DING Zhen Bin JIA Qing Fei WANG Na TIAN Ru Ting TONG Xin Kui WANG Hui Bo SHAO* Department of Chemistry Hebei Teacher抯 University Shijiazhuang Institute of Coal Chemistry Chinese Academy of Science Taiyuan De 《中国化学快报》2001,(12)
Schiff base and its metal complex have attracted much attention because of their wide applications in biomedicine and their specific character in photochromic field1. Up to now, reports about Schiff base mainly covered its synthesis and structure2,3. To the best of our knowledge, there is no paper dealing with Schiff base using electrochemical impedance spectroscopy technique by forming self-assembled monolayer. The complexation of Schiff base with the transition metal ions has been confir… 相似文献
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Self-assembled monolayer of 8-mercaptoquinoline (MQ) on the surface of gold from MQ dilute ethanolic solutions is investigated by electrochemical methods. Some aqueous redox probes, such as ferrocene carboxylic acid and Fe(CN)6
4–/3– can sufficiently diffuse into the monolayer because significant diffusion-limited current peaks are observed when the redox reactions take place, showing that the monolayer is very loosely packed or dominated by defects. However, the study on the electron transfer of other aqueous probes, such as Cu2+ and Ru(NH3)6
3+/2+, confirm that the monolayer can block the electron transfer on the gold electrode surface rather effectively for its low ratio of pinhole defects. These studies show that the MQ monolayer on the electrode can provide an excellent barrier for penetration of some probes but cannot resist the penetration of other probes effectively. The unusual properties of the self-assembled monolayers are attributed to the entity of the very large heterocyclic moiety. 相似文献
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《Journal of Coordination Chemistry》2012,65(24):4194-4209
AbstractBy spectrophotometric titration, 1H NMR and cyclic voltammetry the processes of Co(II)-5,10,15,20-tetraphenylporphyrin, Co(II)-5,10,15,20-tetraphenyl-2,3,7,8,12,13,17,18-tetrabenzoporphyrin, Co(II)-2,3,7,8,12,13,17,18-octaphenyl-5,10,15,20-tetraazaporphyrin, Co(II)-2,3,7,8,12,13,17,18-octa(4-bromphenyl)-5,10,15,20-tetraazaporphyrin and Co(II)-2,3,7,8,12,13,17,18-octa(4-nitrophenyl)-5,10,15,20-tetraazaporphyrin interaction with imidazole (Im) in benzene in the presence and absence of atmospheric oxygen has been investigated. If the Co(II)-porphyrins with high Epc upon complexation with the imidazole form stable mono-axial complexes Co(II)P(Im), then the Co(II)-porphyrins with low Epc are oxidized into low-spin six-coordinate Co(III)-porphyrins with formation of bis-axial complexes Co(III)P(Im)2. The thermodynamic and kinetic parameters of the coordination and oxidation processes have been calculated and corresponding structural correlations have been carried out. 相似文献
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YU Hua-zhong ZHAO Jian-wei WANG Yong-qiang CHENG Ji-zhi CAI Sheng-min LIU Zhong-fan 《高等学校化学学报》1995,16(Z1):138
The self-assembled monolayers (SAMs). which were prepared by spontaneous adsorption of cysteamine on gold surface, were characterized using contact-angle titrations. Contact-angle titration data acquired for the cysteamine SAMs exhibited a smooth transition in contact angle between plateau regions at low and high pH value. The surface pKb, was estimated to be 1.8±0.2, much lower than that in solution. The electroactive azobenzene group was anchored to the monolayer via amide surface reaction. Thus the formed SAMs were further subjected to exchange in dilute pentanethiol soluition. At each stage of modification, the surface was monitored by con-tact-angle titration and cyclic voltanimetry. It was found that the titration curves obviously shifted to the higher contact-angle direction with the increase of surface hydrophobicity. The results are in good agreement with the cyclic voltammetric measurements, demonstrating that the contact-angle titration is a useful technique for monitoring the step by step surface reactions. 相似文献
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Mononuclear copper(Ⅱ), nickel(Ⅱ) and cobalt(Ⅲ) tetracoordinate macrocyclic complexes were synthesized and spectroscopically characterized. The crystal structure of the three compounds were determined by X-ray crystallography. The electrochemical experimental results indicate that the three complexes could interact with DNA mainly by electrostatic interaction. The interaction of tetracoordinate macrocyclic cobalt(Ⅲ) complex with DNA was studied by cyclic voltammetry and UV-vis spectroscopy. The experimental results reveal that tetracoordinate macrocyc- lic cobalt(Ⅲ) complex could interact with DNA by electrostatic interaction to form a 1 : 1 DNA association complex with a binding constant of 7.50 ×10^3 L·mol^-1. 相似文献
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The phase relationship in the pseudobinary Co3V2O8-CoMoO4 system have been determined by differential thermal analysis (DTA) and X-ray diffraction (XRD). A new compound Co2.5 VMoO8, stable up to 1080±5°C has been found in the system. The results obtained are presented in the form of a phase diagram.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献