Role of Hydrogen Bonding on the Self-Organization of Phenyleneethynylenes on Surfaces

Abstract

A series of carboxylic acid substituted phenyleneethynylenes, having a rigid backbone of 2.7 ± 0.1 nm, were synthesized by following the Heck-Cassar-Sonagashira-Hagihara cross-coupling reaction. Hydrogen bonding, through the formation of cyclic dimers of carboxylic acid, is more preferred over catemeric structures in all the molecular systems under investigation. The formation of extended two-dimensional patterns on highly oriented pyrolitic graphite (HOPG) surface is dictated by the position as well as number of the carboxylic acid groups on the phenyleneethynylenes. Highly ordered extended arrangements, in the linear and stepwise fashion, were observed when the carboxylic acid groups are attached in the para and meta positions of phenyleneethynylenes. The vital role of the number of carboxylic acid on the organization of molecules is evident in the case of tetracarboxylic acid derivative wherein a Kagome-type structure was observed. Further, the coassembly of two types of phenyleneethynylenes was achieved on HOPG surface through acid base interaction.

Two‐Dimensional Nanoporous Networks Formed by Liquid‐to‐Solid Transfer of Hydrogen‐Bonded Macrocycles Built from DNA Bases

“…These discrete tetramers then pack in 2D by establishing secondary interactions between H‐bonding donor and acceptor groups that do not participate in Watson–Crick pairing. However, these interactions are different for GC2 and AU2 and thus lead to distinct network arrangements, as previously shown for other H‐bonded systems 1h. In the first case, G‐G double H‐bonding interactions between aminopyridine‐type fragments (Figure 2 d) are established, leading to regular lattices in which the rings interact through their G edges.…”

Self-organization of monodentate organic molecules on a solid surface — A Monte Carlo and transfer-matrix study

“…[8][9][10][11][12][13][14][15][16][17]; 2) specific interactions between adsorbed molecules [18][19][20][21][22][23][24][25][26].…”

Self-assembled organic and hybrid materials derived from oligo-(p-phenyleneethynylenes)

“…The Thomas group synthesized and crystallized several oxyhexyl side-chain functionalized OPE backbones with different end-capping functional groups to investigate their structure and their self-organization on conducting surfaces. 10,56,59 They revealed a host of supramolecular interactions which lead to herringbone and criss-cross packing. Kulkarni and co-workers also synthesized OPEs with side chains varying from methyl to hexyl and studied the effect of packing on emission properties.…”

“…However, one such class of oligomers that stand out from the rest are called oligo-phenyleneethynylenes (OPEs). [6][7][8][9][10] OPEs are known to exhibit an excellent conducting profile, quantum efficiency and solution processability when compared to other conjugated species. 3,6,9 Quantum yield, emissive wavelength, and absorption profile are sensitive to the specific environment created by the end groups and side chains contained in the OPE backbone.…”