Bhattacharjee Rameswar, Jervis Henry, McCormack Megan E, Petrukhina Marina A, Kertesz Miklos
Department of Chemistry and Institute of Soft Matter, Georgetown University, 37th and O Streets, NW, Washington, D.C. 20057-1227, United States.
Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, New York 12222, United States.
J Am Chem Soc. 2024 Apr 17;146(15):10465-10477. doi: 10.1021/jacs.3c14065. Epub 2024 Apr 5.
Perylene (PER) is a prototype of polycyclic aromatic hydrocarbons (PAHs), which play a pivotal role in various functional and electronic materials due to favorable molecule-to-molecule overlaps, which enhance electronic transport. This study provides guidelines regarding the impact of molecular charge on pancake bonding, a form of strong π-stacking interaction. Pancake bonding significantly boosts interaction energies within the monopositive dimer ([(CH)] or PER), crucial for stabilizing aggregation and crystal formation. We discovered energetically feasible sliding and rotation pathways within the [(CH)] dimer, connecting different configurations found in the Cambridge Structural Database (CSD). The dimer's charge profoundly influences the pancake bond order (PBO) and the strength and structural preferences of pancake bonding. The most stable configuration is found in the monocationic state (PER), featuring a pancake bond order of 1/2 with one-electron multicenter bonding (1e/mc) with similar characteristics for charge -1. Increasing the total charge of the dimer to +2 or -2 leads to an unstable local minimum. Diverse distribution of pancake bonding types present in crystal structures is interpreted with modeling based on dimer computations with varying charges.
苝（PER）是多环芳烃（PAHs）的一个典型例子，由于其分子间有利的重叠，在各种功能材料和电子材料中起着关键作用，这种重叠增强了电子传输。本研究提供了有关分子电荷对煎饼键合（一种强π-堆积相互作用形式）影响的指导原则。煎饼键合显著提高了单正离子二聚体（[(CH)]或PER）内的相互作用能，这对于稳定聚集和晶体形成至关重要。我们在[(CH)]二聚体内发现了能量上可行的滑动和旋转途径，这些途径连接了剑桥结构数据库（CSD）中发现的不同构型。二聚体的电荷对煎饼键序（PBO）以及煎饼键合的强度和结构偏好有深远影响。最稳定的构型出现在单阳离子状态（PER），其煎饼键序为1/2，具有单电子多中心键合（1e/mc），对于电荷为 -1时具有类似特征。将二聚体的总电荷增加到 +2或 -2会导致不稳定的局部最小值。基于不同电荷的二聚体计算建模，解释了晶体结构中存在的各种煎饼键合类型的分布。
