Mechanisms of Covalent Dimerization on a Bulk Insulating Surface
Mechanisms of Covalent Dimerization on a Bulk Insulating Surface
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本体绝缘表面上的共价二聚机制
DOI：
10.1021/acs.jpcc.7b02687
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发表时间：
2017-05-11
影响因子：
3.7
通讯作者：
Floris, Andrea
中科院分区：
文献类型：
--
作者：
Guo, Chunyan;Wang, Yu;Floris, Andrea
结合密度泛函理论和高分辨率NC-AFM实验，我们研究了4-碘苯甲酸（IBA）有机分子在方解石（10.4）绝缘表面上共价二聚的表面反应机理.当在580 K退火时，分子组装成共价结合的二聚体的一维链。这些链具有独特的取向，并由一系列复杂的过程产生，包括名义上相当昂贵的双脱卤反应，然后是二聚反应。首先，专注于后两个过程，并使用轻推弹性带方法，我们分析了一些可能的机制，涉及一个和两个分子，我们隔离的关键方面促进方解石上的反应。第二，我们发现，绝缘表面起着积极的作用，作为催化剂，通过确定两个相关的过程：一个表现出独立的脱卤和第二个，高度非平凡的放热反应后的化学吸附分子的中间状态。
Combining density functional theory and high-resolution NC-AFM experiments, we have studied the on-surface reaction mechanisms responsible for the covalent dimerization of 4-iodobenzoic acid (IBA) organic molecules on the calcite (10.4) insulating surface. When annealed at 580 K, the molecules assemble in one-dimensional chains of covalently bound dimers. The chains have a unique orientation and result from a complex set of processes, including a nominally rather costly double dehalogenation reaction followed by dimerization. First, focusing on the latter two processes and using the nudged elastic band method, we analyze a number of possible mechanisms involving one and two molecules, and we isolate the key aspects facilitating the reaction on calcite. Second, we find that the insulating surface plays an active role as a catalyst by identifying two relevant processes: one exhibiting an intermediate state of chemisorbed molecules after independent dehalogenations and a second, highly nontrivial exothermic ...