Rohini K, Sylvinson Daniel M R, Swathi R S
School of Chemistry, Indian Institute of Science Education and Research-Thiruvananthapuram , Kerala, India 695016.
J Phys Chem A. 2015 Nov 5;119(44):10935-45. doi: 10.1021/acs.jpca.5b05702. Epub 2015 Oct 23.
Understanding molecular interactions with monolayers and bilayers of graphene and its derivatized forms is very important because of their fundamental role in gas sensing and separation, gas storage, catalysis, etc. Herein, motivated by the recent realization of graphene-based sensors for the detection of single gas molecules, we use density functional theory to study the noncovalent interactions of molecules and molecular clusters with graphene, graphene oxide, and graphane, which are represented by coronene-based molecular model systems, C24H12 (coronene), C24OH12 (coroepoxide), and C24H36 (perhydrocoronene), respectively. The objective is to understand the structural and energetic changes that occur as a result of adsorption on monolayers and intercalation within bilayers. To begin with, the interactions of coronene, coroepoxide, and perhydrocoronene with a variety of small molecules like HF, HCl, HBr, H2O, H2S, NH3, and CH4 are studied. Subsequently, the binding of coronene and coroepoxide substrates with molecular clusters of HF, H2O, and NH3 is studied to understand the strength of adsorption on the substrates and the effect of substrates on hydrogen-bonding interactions within the molecular clusters. Further, bilayers of the model systems, namely, coronene-coronene, coronene-coroepoxide, and two configurations of coroepoxide-coroepoxide (one in which the oxygen atoms are facing each other and the other in which they do not face each other) are generated. The energetics for the nanoscale confinement or intercalation of the clusters within the bilayers along with the impact of the intercalation on the intermolecular hydrogen-bonding interactions are investigated. Our coronene-based model systems can provide a simple way of describing the rather complex events that occur in representative regions of graphene-based heterogeneous substrates.
由于石墨烯及其衍生形式的单层和双层在气体传感与分离、气体存储、催化等方面具有重要的基础作用，了解分子与它们的相互作用非常重要。在此，受近期基于石墨烯的单气体分子检测传感器实现的启发，我们使用密度泛函理论研究分子和分子簇与石墨烯、氧化石墨烯和石墨烷的非共价相互作用，分别用基于并五苯的分子模型系统C24H12（并五苯）、C24OH12（并五苯环氧化物）和C24H36（全氢并五苯）来表示。目的是了解由于吸附在单层上以及嵌入双层中而发生的结构和能量变化。首先，研究并五苯、并五苯环氧化物和全氢并五苯与各种小分子如HF、HCl、HBr、H2O、H2S、NH3和CH4的相互作用。随后，研究并五苯和并五苯环氧化物底物与HF、H2O和NH3分子簇的结合，以了解在底物上的吸附强度以及底物对分子簇内氢键相互作用的影响。此外，生成了模型系统的双层，即并五苯 - 并五苯、并五苯 - 并五苯环氧化物以及并五苯环氧化物 - 并五苯环氧化物的两种构型（一种是氧原子相对，另一种是氧原子不相对）。研究了分子簇在双层内的纳米级限制或嵌入的能量学以及嵌入对分子间氢键相互作用的影响。我们基于并五苯的模型系统可以提供一种简单的方式来描述在基于石墨烯的异质底物的代表性区域中发生的相当复杂的事件。
