Conducting π Columns of Highly Symmetric Coronene, The Smallest Fragment of Graphene

Abstract

Coronene, which is the smallest D6h -symmetric polycyclic aromatic hydrocarbon, attracts particular attention as a basic component of electronic materials because it is the smallest fragment of graphene. However, carrier generation by physical methods, such as photo- or electric field-effect, has barely been studied, primarily because of the poor π-conduction pathway in pristine coronene solid. In this work we have developed unprecedented π-stacking columns of cationic coronene molecules by electrochemical hole-doping with polyoxometallate dianions. The face-to-face π-π interactions as well as the partially charged state lead to electrical conductivity at room temperature of up to 3 S cm(-1) , which is more than 10 orders of magnitude higher than that of pristine coronene solid. Additionally, the robust π-π interactions strongly suppress the in-plane rotation of the coronene molecules, which has allowed the first direct observation of the static Jahn-Teller distortion of cationic coronene molecules.

Dependence upon charge of the vibrational spectra of small Polycyclic Aromatic Hydrocarbon clusters: the example of pyrene

“…For instance, their role in flame chemistry is still under debate, as they could act as possible precursors of soot particles through oligomerization [1][2][3][4][5][6][7][8][9][10][11][12]. The optical and transport properties of PAH clusters are also investigated in the context of organic solar cell design [12][13][14][15][16][17][18][19][20][21]. Carbonaceous compounds involving PAH are studied as pollutants in both environmental and atmospheric science [22][23][24][25][26].…”

Bending for Better: Flexible Organic Single Crystals with Controllable Curvature and Curvature‐Related Conductivity for Customized Electronic Devices

“…Structurally, strong face‐to‐face cofacial parallel stacked π–π interactions along the growth direction [010] (Figure 1 d,e,k), and weak edge‐to‐face T‐shape π‐π interactions along the [001] direction coexist, bringing only very weak dispersive interactions along the [10 ] direction (Figure 1 d,e,l, Figure S20,S21 and Table S3 for energy frameworks analysis), [6b, 14] which represents a remarkably bendable nature of the (10 ) plane, [1f, 8j, 9c, 15] consistent with the experimental facts that the crystals show elasticity when applying force at (10 ) plane and show brittleness when applying force at (001) plane (Figure 1 b,c,f,g, Movie S3, Figure S3,S17). However, the inherent herringbone packing motif without effective two‐dimensional π‐π overlap determines limited charge transport, [13a, 16] resulting in a conductivity less than 10 −12 S cm −1 [17] . Nevertheless, the π–π interactions are very sensitive to slight perturbations in distance and angle between adjacent molecules (Figure 1 e,k,l), which will theoretically affect the π electron density and motion associated with the overall electrical properties [18] .…”

“…Towards these objectives,w es eek for an appropriate crystal system whose property is sensitive enough to structural distortion at the molecular level, for af easible function regulation via controlling the bending degree.Inspired by the world-shaking magic-angle twisted bilayer graphene,w hich gets as harp increase in conductivity by merely small-angle twisting between two graphene layers, [12] the minimum molecular graphene,c oronene, [13] was locked as the model compound. Coronene is ar igid molecule and able to form one-dimensional crystals with mechanical flexibility and controllable size by solution self-assembly,w hich is reliable and easy-to-implement (Figure 1a-g).…”

Continuum Modelling for Interacting Coronene Molecules with a Carbon Nanotube

“…In order to combat the inability of coronene to self organise into long stacked columns [17], carbon nanotubes are used to confine the stacking [18][19][20][21][22][23]. Encapsulating coronenes into carbon nanotubes is typically done through vapour-phase doping [18,24].…”