Structural Evolution of Hexa-peri-hexabenzocoronene Adlayers in Heteroepitaxy on n-Pentacontane Template Monolayers

Abstract

The growth and structure of self-assembled adlayers of hexakis(n-dodecyl)-peri-hexabenzocoronene (HBC-C12) adsorbed on highly ordered pyrolitic graphite (HOPG) decorated by an n-pentacontane (n-C50H102) monolayer have been investigated by scanning tunneling microscopy (STM). Whereas on HOPG the HBC-C12 molecules readily self-assemble into a unique stable 2D structure, on the [n-C50H102 monolayer/graphite] system we observe morphological phase transitions with formation of time dependent alpha, beta, and gamma phases (alpha-->beta-->gamma). The initial alpha-phase is similar to that obtained on bare graphite, while intermediate beta- and final gamma-structures present molecular dimers and rows, respectively. The observed two-dimensional polymorphism is due to weak interaction between HBC-C12 molecules and n-C50H102-modified graphite substrate. Our results constitute an important step toward the control of the growth and structure of highly ordered monolayers of functional conjugated molecules by modifying the graphite surface with an n-alkane monolayer of appropriate chain length.

Epitaxial ordering of a perylenetetracarboxylic diimide-melamine supramolecular network driven by the Au(111)-(22×3) reconstruction

“…[1][2][3][4][5] Another method exploits intermolecular interactions by mixing different molecular species to form extended networks. [5][6][7][8][9] The resulting supramolecular architecture can be tailored by modifying the functionality and the structure of the molecular building blocks. Further tuning can be achieved by changing the sample temperature 10 or relative molecular abundance during the preparation process.…”

Immobilization of paracetamol and benzocaine pro-drug derivatives as long-range self-organized monolayers on graphite

“…Being highly selective and directional while moderately strong, H-bonds allow to build complex supramolecular interactions from simple molecular blocks [15]. Van der Waals forces helps anchoring molecules onto the surface as shown in previous studies [16][17][18]. Combining both interactions has proven extremely successful in self-assembling a large range of molecules on atomically flat substrates, including those of biological interest [19].…”

Hexa-peri-hexabenzocoronenes – Controlling their Self-Assembly by Engineering the Lateral Substituents

“…[38] Furthermore, perfluorinated chains have a much more hydrophobic character than alkyl chains, but are fairly lipophobic as well. [39] Thus, the decoration of HBCs with perfluoroalkyl chains instead of alkyl ones, whose crystallization leads to the undesired lateral aggregation of the HBC stacks, [40] should greatly reduce the tendency for lateral interaction without altering the desired π-π-stacking. This may also be a possible reason why perfluoroalkylated HBCs have much higher transition temperatures to the mesophase when compared to their purely n-alkylated homologues.…”