Self-assembled monolayers of oligophenylenecarboxylic acids on silver formed at the liquid-solid interface

Hannah Aitchison, Hao Lu, Simon W. L. Hogan, Herbert Früchtl, Izabela Cebula, Michael Zharnikov, Manfred Buck

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

A series of para-oligophenylene mono- and dicarboxylic acids (R-(C6H4)nCOOH, n=1-3, R=H,COOH) was studied. Adsorbed on Au(111)/mica modified by an underpotential deposited bilayer of Ag, the self-assembled monolayers (SAMs) were analysed by near edge X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy and scanning tunneling microscopy. In all cases SAMs are formed with molecules adopting an upright orientation and anchored to the substrate by a carboxylate. Except benzoic acid, all SAMs could be imaged at molecular resolution, which revealed highly crystalline layers with a dense molecular packing. The structures of the SAMs are described by a rectangular (5×√3) unit cell for the prevailing phase of the monocarboxylic acids and an oblique (√93×√133) unit cell for the dicarboxylic acids, thus, evidencing a pronounced influence of the second COOH moiety on the SAM structure. Density functional theory calculations suggest that hydrogen bonding between the SAM terminating COOH moieties accounts for the difference. Contrasting other classes of SAMs, the systems studied here are determined by intermolecular interactions whereas molecule-substrate interactions play a secondary role. Thus, eliminating problems arising from the mismatch between the molecular and substrate lattices, coordinatively bonded carboxylic acids on silver should provide considerable flexibility in the design of SAM structures.
LanguageEnglish
Number of pages18
JournalLangmuir
DOIs
Publication statusPublished - 2 Sep 2016

Fingerprint

Self assembled monolayers
liquid-solid interfaces
Silver
dicarboxylic acids
silver
acids
Acids
Liquids
benzoic acid
cells
mica
stopping
carboxylic acids
Dicarboxylic Acids
carboxylates
scanning tunneling microscopy
molecules
flexibility
x rays
fine structure

Keywords

  • carboxylic acids
  • metal-organic coordination bonding
  • molecular self-assembly
  • liquid-solid interface
  • underpotential deposition
  • oligophenylenecarboxylic acids
  • silver

Cite this

Aitchison, Hannah ; Lu, Hao ; Hogan, Simon W. L. ; Früchtl, Herbert ; Cebula, Izabela ; Zharnikov, Michael ; Buck, Manfred. / Self-assembled monolayers of oligophenylenecarboxylic acids on silver formed at the liquid-solid interface. In: Langmuir. 2016.
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abstract = "A series of para-oligophenylene mono- and dicarboxylic acids (R-(C6H4)nCOOH, n=1-3, R=H,COOH) was studied. Adsorbed on Au(111)/mica modified by an underpotential deposited bilayer of Ag, the self-assembled monolayers (SAMs) were analysed by near edge X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy and scanning tunneling microscopy. In all cases SAMs are formed with molecules adopting an upright orientation and anchored to the substrate by a carboxylate. Except benzoic acid, all SAMs could be imaged at molecular resolution, which revealed highly crystalline layers with a dense molecular packing. The structures of the SAMs are described by a rectangular (5×√3) unit cell for the prevailing phase of the monocarboxylic acids and an oblique (√93×√133) unit cell for the dicarboxylic acids, thus, evidencing a pronounced influence of the second COOH moiety on the SAM structure. Density functional theory calculations suggest that hydrogen bonding between the SAM terminating COOH moieties accounts for the difference. Contrasting other classes of SAMs, the systems studied here are determined by intermolecular interactions whereas molecule-substrate interactions play a secondary role. Thus, eliminating problems arising from the mismatch between the molecular and substrate lattices, coordinatively bonded carboxylic acids on silver should provide considerable flexibility in the design of SAM structures.",
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Self-assembled monolayers of oligophenylenecarboxylic acids on silver formed at the liquid-solid interface. / Aitchison, Hannah; Lu, Hao; Hogan, Simon W. L.; Früchtl, Herbert; Cebula, Izabela; Zharnikov, Michael; Buck, Manfred.

In: Langmuir, 02.09.2016.

Research output: Contribution to journalArticle

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T1 - Self-assembled monolayers of oligophenylenecarboxylic acids on silver formed at the liquid-solid interface

AU - Aitchison, Hannah

AU - Lu, Hao

AU - Hogan, Simon W. L.

AU - Früchtl, Herbert

AU - Cebula, Izabela

AU - Zharnikov, Michael

AU - Buck, Manfred

N1 - This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Langmuir, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.langmuir.6b01773

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Y1 - 2016/9/2

N2 - A series of para-oligophenylene mono- and dicarboxylic acids (R-(C6H4)nCOOH, n=1-3, R=H,COOH) was studied. Adsorbed on Au(111)/mica modified by an underpotential deposited bilayer of Ag, the self-assembled monolayers (SAMs) were analysed by near edge X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy and scanning tunneling microscopy. In all cases SAMs are formed with molecules adopting an upright orientation and anchored to the substrate by a carboxylate. Except benzoic acid, all SAMs could be imaged at molecular resolution, which revealed highly crystalline layers with a dense molecular packing. The structures of the SAMs are described by a rectangular (5×√3) unit cell for the prevailing phase of the monocarboxylic acids and an oblique (√93×√133) unit cell for the dicarboxylic acids, thus, evidencing a pronounced influence of the second COOH moiety on the SAM structure. Density functional theory calculations suggest that hydrogen bonding between the SAM terminating COOH moieties accounts for the difference. Contrasting other classes of SAMs, the systems studied here are determined by intermolecular interactions whereas molecule-substrate interactions play a secondary role. Thus, eliminating problems arising from the mismatch between the molecular and substrate lattices, coordinatively bonded carboxylic acids on silver should provide considerable flexibility in the design of SAM structures.

AB - A series of para-oligophenylene mono- and dicarboxylic acids (R-(C6H4)nCOOH, n=1-3, R=H,COOH) was studied. Adsorbed on Au(111)/mica modified by an underpotential deposited bilayer of Ag, the self-assembled monolayers (SAMs) were analysed by near edge X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy and scanning tunneling microscopy. In all cases SAMs are formed with molecules adopting an upright orientation and anchored to the substrate by a carboxylate. Except benzoic acid, all SAMs could be imaged at molecular resolution, which revealed highly crystalline layers with a dense molecular packing. The structures of the SAMs are described by a rectangular (5×√3) unit cell for the prevailing phase of the monocarboxylic acids and an oblique (√93×√133) unit cell for the dicarboxylic acids, thus, evidencing a pronounced influence of the second COOH moiety on the SAM structure. Density functional theory calculations suggest that hydrogen bonding between the SAM terminating COOH moieties accounts for the difference. Contrasting other classes of SAMs, the systems studied here are determined by intermolecular interactions whereas molecule-substrate interactions play a secondary role. Thus, eliminating problems arising from the mismatch between the molecular and substrate lattices, coordinatively bonded carboxylic acids on silver should provide considerable flexibility in the design of SAM structures.

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KW - oligophenylenecarboxylic acids

KW - silver

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