两个三维(3D)卟啉的共价有机骨架,PCOF-1和PCOF-2 ,合成通过的亚胺缩合的平面卟啉四胺(TAPP或TABPP)和基于的3,3位阻的刚性四面体醛' ,5,5′-四(4-甲酰基苯基)二甲磺酰基(TFBM)。通过FT-IR和13 C CP-MAS固态NMR光谱研究了PCOF-1和PCOF-2的结构。粉末X射线衍射图显示出明显的结晶度,在PCOF-1的3.28°和3.75°处有两个强峰,在PCOF-2的2.63°和2.98°处有两个强峰。。结构仿真证实了它们的3D金红石型(pts)拓扑结构具有两种不同的孔径。X射线单晶衍射显示,构造块TFBM的扭曲四面体结构具有两个119°和107.8°的二面角,而模型化合物(MC)的平面正方形结构具有176.5°的扩展角。PCOF-1和PCOF-2的Brunauer-Emmett-Teller(BET)表面积分别为316和234 m 2 g -1。用
Kinetics of oxidation of benzyl alcohols by the dication and radical cation of ABTS. Comparison with laccase–ABTS oxidations: an apparent paradox
摘要:
漆酶是一种蓝色铜氧化酶,由于其适中的还原电位,它只能通过电子转移氧化酚类化合物。然而,在存在ABTS(2,2'-亚氮二异丁基-3-乙基苯硫唑-6-磺酸盐)作为还原介质的情况下,漆酶可以与更难以氧化的非酚类底物反应,如苄醇。这些介导氧化反应中ABTS的作用被进行了研究。漆酶与ABTS的还原相互作用可以在原位产生两种反应中间体,分别为ABTS++或ABTS•+。这些物质已经通过与Ce(IV)或Co(III)盐的氧化反应独立生成,并在动力学研究中测试了它们作为单电子氧化剂的效率;同时对ABTS++提供了Marcus处理。在这些基础上,ABTS++作为漆酶-ABTS氧化反应中的反应中间体的介入似乎不太可能,因为明确生成ABTS++且其存活时间足以作为可扩散介质的实验条件过于苛刻(2 M H2SO4溶液),且与酶的操作不兼容。同样,ABTS•+在漆酶-ABTS氧化反应中似乎是一个重要性有限的中间体,因为这种较弱的单电子氧化剂无法直接与许多漆酶-ABTS可以氧化的非酚类底物反应。为了解决这一矛盾,另有一种建议认为在漆酶-ABTS反应过程中,通过水解原位生成了ABTS++或ABTS•+的降解副产品,这些副产品可能负责观察到的非酚类化合物的氧化。
Kinetics of oxidation of benzyl alcohols by the dication and radical cation of ABTS. Comparison with laccase–ABTS oxidations: an apparent paradox
摘要:
漆酶是一种蓝色铜氧化酶,由于其适中的还原电位,它只能通过电子转移氧化酚类化合物。然而,在存在ABTS(2,2'-亚氮二异丁基-3-乙基苯硫唑-6-磺酸盐)作为还原介质的情况下,漆酶可以与更难以氧化的非酚类底物反应,如苄醇。这些介导氧化反应中ABTS的作用被进行了研究。漆酶与ABTS的还原相互作用可以在原位产生两种反应中间体,分别为ABTS++或ABTS•+。这些物质已经通过与Ce(IV)或Co(III)盐的氧化反应独立生成,并在动力学研究中测试了它们作为单电子氧化剂的效率;同时对ABTS++提供了Marcus处理。在这些基础上,ABTS++作为漆酶-ABTS氧化反应中的反应中间体的介入似乎不太可能,因为明确生成ABTS++且其存活时间足以作为可扩散介质的实验条件过于苛刻(2 M H2SO4溶液),且与酶的操作不兼容。同样,ABTS•+在漆酶-ABTS氧化反应中似乎是一个重要性有限的中间体,因为这种较弱的单电子氧化剂无法直接与许多漆酶-ABTS可以氧化的非酚类底物反应。为了解决这一矛盾,另有一种建议认为在漆酶-ABTS反应过程中,通过水解原位生成了ABTS++或ABTS•+的降解副产品,这些副产品可能负责观察到的非酚类化合物的氧化。
Acyl/aroylperoxyl radicals: a comparative study of the reactivity of peroxyl radicals resulting from the α-cleavage of ketones
作者:Ali El-Agamey、David J. McGarvey
DOI:10.1039/b109309f
日期:2002.4.17
salt (ABTS2−) as a selective radical probe, nanosecond laser flash photolysis (LFP) and competitive kinetic methods have been used to investigate the reactions of acyl/aroylperoxyl radicals derived from the addition of oxygen to the α-cleavage products of variousketones in methanol. The selectivity of ABTS2− for acyl/aroylperoxyl radicals (as opposed to alkylperoxyl radicals), under the experimental conditions
Formation and decay of the ABTS derived radical cation: A comparison of different preparation procedures
作者:Carola Henriquez、Carolina Aliaga、Eduardo Lissi
DOI:10.1002/kin.10094
日期:——
free radical scavengers, radicalcations obtained employing AAPH as oxidant can be used only at low temperatures, conditions where further decomposition of the remaining AAPH is minimized. The best results are obtained with ABTSderivedradicals generated in the reaction of PDS with an ABTS/PDS concentration ratio equal (or higher) to two. However, even with radicals prepared by this procedure, stoichiometric
various solutions. Due to the large surface area and the appropriate pore size, PCOF-Fe exhibited excellent biocatalytic catalytic performance, while PCOF-Co exhibited good electrocatalytic activity towards oxygen evolution reactions. These results indicate that 3D porphyrin-based COFs constructed from the tetrahedralbuildingblock with steric hindrance are promising candidates for single-site catalysis
两个三维(3D)卟啉的共价有机骨架,PCOF-1和PCOF-2 ,合成通过的亚胺缩合的平面卟啉四胺(TAPP或TABPP)和基于的3,3位阻的刚性四面体醛' ,5,5′-四(4-甲酰基苯基)二甲磺酰基(TFBM)。通过FT-IR和13 C CP-MAS固态NMR光谱研究了PCOF-1和PCOF-2的结构。粉末X射线衍射图显示出明显的结晶度,在PCOF-1的3.28°和3.75°处有两个强峰,在PCOF-2的2.63°和2.98°处有两个强峰。。结构仿真证实了它们的3D金红石型(pts)拓扑结构具有两种不同的孔径。X射线单晶衍射显示,构造块TFBM的扭曲四面体结构具有两个119°和107.8°的二面角,而模型化合物(MC)的平面正方形结构具有176.5°的扩展角。PCOF-1和PCOF-2的Brunauer-Emmett-Teller(BET)表面积分别为316和234 m 2 g -1。用
Derivation and Decoration of Nets with Trigonal-Prismatic Nodes: A Unique Route to Reticular Synthesis of Metal–Organic Frameworks
5-thiophenedicarboxylic acid). Furthermore, the trigonal prism unit can be considered as a double SBU derived from triply bound triangular frusta. By considering theoretical derived nets for linking this trigonal-prismatic node with ditopic, tritopic, and tetratopic linkers, we have synthesized and characterized a new family of MOFs that adopt the decorated lon, jea, and xai nets, respectively. Pore sizes have
Reaction of Cyclic Nitroxides with Nitrogen Dioxide: The Intermediacy of the Oxoammonium Cations
作者:Sara Goldstein、Amram Samuni、Angelo Russo
DOI:10.1021/ja035286x
日期:2003.7.1
), which effectively scavenge the product of this reaction, the oxoammonium cation. The rate constants for the reactions of .NO2 with these nitroxides were determined to be (7-8) x 10(8) M(-)(1) s(-)(1), independent of the pH over the range 3.9-10.2. These are among the highest rate constants measured for .NO2 and are close to that of the reaction of .NO2 with .NO, that is, 1.1 x 10(9) M(-1) s(-1)