A study of planar anchor groups for graphene-based single-molecule electronics

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. To identify families of stable planar anchor groups for use in single molecule electronics, we report detailed results for the binding energies of two families of anthracene and pyrene derivatives adsorbed onto graphene. We find that all the selected derivatives functionalized with either electron donating or electron accepting substituents bind more strongly to graphene than the parent non-functionalized anthracene or pyrene. The binding energy is sensitive to the detailed atomic alignment of substituent groups over the graphene substrate leading to larger than expected binding energies for -OH and -CN derivatives. Furthermore, the ordering of the binding energies within the anthracene and pyrene series does not simply follow the electron affinities of the substituents. Energy barriers to rotation or displacement on the graphene surface are much lower than binding energies for adsorption and therefore at room temperature, although the molecules are bound to the graphene, they are almost free to move along the graphene surface. Binding energies can be increased by incorporating electrically inert side chains and are sensitive to the conformation of such chains. © 2014 AIP Publishing LLC.

Noncovalent Interaction of Graphene with Heterocyclic Compounds: Benzene, Imidazole, Tetracene, and Imidazophenazines

“…Somereviewsd evoted to the analysis of non-covalent interactions between aromatic compounds and graphene have been recently published. [9][10][11][12][13][14] Several theoretical studies have focused on the interactions between graphene and different heterocyclic aromatich ydrocarbons, such as benzene, [15][16][17][18][19][20][21][22][23][24][25] naphthalene, [18,21,[24][25][26] anthracene, [27] pentacene, [28] pyrene, [24,[27][28][29][30][31] coronene, [22,24,32] and ovalene. [22,24] It was established that these flat-structure molecules bind to graphene sheets in the planar stack orientation with the interaction energy whichi ncreases with the increasing intermolecular contact area.…”

“…[33][34][35][36] The interaction energy between aromatic hydrocarbonsa nd graphene increases upon substitution with both electron-donating and -withdrawing groups, as identified by DFT calculations. [25,27,28] It was shown that -CN and -OH groups added to anthracene and pyrene molecules are effectives ubstituents for enhancing binding to graphene. [27] It was determined that the binding energy is sensitive to the detailed atomica lignment of the substituent groups over the graphene sheet.…”

“…[25,27,28] It was shown that -CN and -OH groups added to anthracene and pyrene molecules are effectives ubstituents for enhancing binding to graphene. [27] It was determined that the binding energy is sensitive to the detailed atomica lignment of the substituent groups over the graphene sheet. [27] Twob ackside amino groups added to naphthalene enhance its interaction energy with graphene by 5.2 kcal mol À1 .…”

“…[27] It was determined that the binding energy is sensitive to the detailed atomica lignment of the substituent groups over the graphene sheet. [27] Twob ackside amino groups added to naphthalene enhance its interaction energy with graphene by 5.2 kcal mol À1 . [28] Note that for af lat configuration of molecules adsorbed on graphene, an increasedn umber of atoms (and electrons)o fb oth the main molecule and substituted groups come in contact with the graphene surfacel eadingt os tronger van der Waals interactions.…”

First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups

“…Thus, these PAH molecules are mobile over the graphene surface at room temperature. 45 PAH-graphene contacts with high thermal stability may be fabricated by attaching suitable side groups onto the PAH molecules, an aspect requiring further investigations in the future.…”