Structure of 3,3:6,6-dibutano-3a-methyl-6a-phenyltetrahydrofuro[3,2-b]furan-2,5-dione

Journal of Structural Chemistry - In the interaction of methyl 1-bromocyclopentanecarboxylate with zinc and 1-phenylpropan-1,2-dione,...     

The role of induced current density in Steroelectronic effects: Perlin effect

The normal and reverse Perlin effect is usually explained by the redistribution of electron density produced by hyperconjugative mechanisms, which increases the electron population within axial or equatorial proton in normal or reverse effect, respectively. Here an alternative explanation for the Perlin effect is presented on the basis of the topology of the induced current density, which directly determines the nuclear magnetic shielding. Current densities around the C? H bond critical point and intra‐atomic and interatomic contributions to the magnetic shielding explain the observed Perlin effect. The balance between intra‐atomic and interatomic contributions determines the difference in the total atomic shielding. Normal Perlin effect is dominated by intra‐atomic part, whereas reverse effect is dominated by interatomic contribution. © 2015 Wiley Periodicals, Inc.     

表面形貌控制增强铁基载氧体与褐煤化学链燃烧反应活性

为探究载氧体形貌控制获取适用于化学链燃烧的高活性表面结构载氧体的可行性,以Fe2O3作为模型载氧体,从理论上对比研究Fe2O3的高弥勒指数晶面(104)和Fe2O3自然裸露的最主要晶面之一(001)的表面电子特性,结果表明,Fe2O3(104)的电子结构更有利于表面与煤模型分子的相互作用.基于理论分析结果,从实验上控制制备了单晶载氧体Fe2O3(104)/Al2O3,研究了该载氧体与褐煤的化学链燃烧反应特性.Fe2O3(104)/Al2O3比传统浸渍法制备的载氧体Fe2O3/Al2O3具有更高的反应活性,与理论计算结果一致.元素分析表明,Fe2O3(104)/Al2O3与褐煤反应的积碳量远少于Fe2O3/Al2O3与褐煤反应的积碳量.对比新鲜载氧体及再生后载氧体的结构发现,Fe2O3(104)/Al2O3在反应过程中不断进行氧化还原反应而发生结构弛豫后,仍然能通过氧化再生.这表明形貌控制制备可为化学链燃烧技术开发新型高效载氧体提供新思路.