Surface-confined monomers on electrode surfaces Part 3. Electrochemical reactions and scanning probe microscopy investigations of ω-(N-pyrrolyl) alkanethiol self-assembled monolayers on gold

Willicut, Robert J.; McCarley, Robin L.

doi:10.1016/0003-2670(94)00596-e

Cited by 33 publications

(28 citation statements)

References 20 publications

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“…109 Internal polymerizations of SAMs include conversion of diacetylenes to a conjugated ene -yne structure, 110,111 cross-linking of a terminal vinyl group, 112 hydrolysis and cross-linking of a trimethoxysilane, 113 dehydration of a boronic acid to a borate glass, 114 and electrochemical polymerization of a terminal pyrrole. 115,116 The polymerized SAMs exhibit increased stability towards thermal desorption and greater resistance to exchange with solution thiols.…”

Section: Nonelectrochemical Characterization Of Self-assembled Monolamentioning

confidence: 99%

Self‐Assembled Monolayers on Electrodes

Finklea

2000

Encyclopedia of Analytical Chemistry

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Alkanethiols and related molecules spontaneously adsorb from solution or vapor phase onto oxide‐free metals, especially gold, to form close‐packed oriented monolayers. The ease and flexibility of the self‐assembly process provides a convenient method for altering the properties of the metal as an electrode. The close‐packed hydrocarbon layer blocks access of most solution species to the electrode surface. Consequently, interfacial capacitances are markedly reduced and most electron‐transfer reactions are strongly inhibited. The monolayers also provide a foundation for attachment of additional molecules or molecular layers to electrodes. Self‐assembled monolayers (SAMs) on electrodes have been used in voltammetric methods to improve the analytical sensitivity and to impart greater selectivity towards specific analytes. Redox molecules have been anchored at fixed and controllable distances from the electrode surface, thereby permitting the study of electron‐transfer kinetics over long distances and at large driving forces. The ability of SAMs to inhibit metal corrosion and to promote better adhesion of electroactive polymers has been demonstrated.

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Section: Nonelectrochemical Characterization Of Self-assembled Monolamentioning

confidence: 99%

Self‐Assembled Monolayers on Electrodes

Finklea

2000

Encyclopedia of Analytical Chemistry

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“…AuC n X has been studied using a plethora of analytical techniques and has been at least twice reviewed. , Of the techniques employed, scanning tunneling microscopy (STM) is unique in its ability to characterize structure, nondestructively, in direct space, and with routine single-molecule or single-atom resolution. , This review will not address all experimental and theoretical analyses, only those that employed STM to study AuC n X. − ...…”

Section: Introductionmentioning

confidence: 99%

Characterization of Organosulfur Molecular Monolayers on Au(111) using Scanning Tunneling Microscopy

1997

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“…An irreversible anodic peak was observed near the electrode potential of 0.8 V, which was attributed to oxidation of pyrrolyl units in the SAM. [11][12][13][14] No polymeric wave could be seen in voltammetry cycles subsequent to the first cycle, probably because no special efforts were carried out to remove residual water from the electrolyte solution. 11 Because neither polymeric wave nor pyrrolyl monomer oxidation 31 prior to the CV scans was detected, the number of molecules in the CVactive area could be counted by a ratio of 2e À per molecule, 12,13 using the shaded area in Fig.…”

Section: Molecular Coverage Of Pyc 12 Sh Sammentioning

confidence: 99%

“…McCarley and Willicut have made a major contribution to studies on pyrrolyl-terminated alkanethiol (PyC n SH) SAMs on Au(111) by reporting an electrochemical polymerization of the pyrrolyl endgroups, [11][12][13] which implied possible application of this system to molecular electronics and chemical surface engineering. 14 Although they proposed formation of polymerized patterns on those SAMs by scanning probe-based methods to be viable, there has not yet been a report of success.…”

Section: Introductionmentioning

confidence: 99%

“…[15][16][17] Moreover, there has not been an SPM-based study on the system with molecular or lattice resolution. 11 In this article, we present the first scanning probe microscopy (SPM) study on the structures of PyC n SH SAMs. It is shown that the SAMs (n = 11 or 12) formed at room temperature have a partially disordered structure, while they can transform into an ordered phase by STM scans or thermal annealing.…”

Section: Introductionmentioning

confidence: 99%

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Disorder–order phase change of ω-(N-pyrrolyl)alkanethiol self-assembled monolayers on gold induced by STM scans and thermal activation

Lee

Shik

Kim

et al. 2008

Phys. Chem. Chem. Phys.

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Molecular ordering of pyrrolyl-terminated alkanethiol self-assembled monolayers (PyC(n)SH SAMs) on Au(111) substrates (n = 11 or 12) was investigated by scanning tunneling microscopy (STM) and various spectroscopic methods. The SAMs, which were in a disordered state when formed at room temperature, could be ordered either globally by thermal annealing at 70 degrees C, or locally via stimulation with repetitive STM scans. The ordered phase was characterized by small domains of molecular rows formed along 112[combining macron] directional set with an inter-row corrugation period close to 1.44 nm, in which defects were abundant. Based on the experimental results, the molecular arrangement in the ordered PyC(n)SH SAM was proposed to be a (5x radical3)rect structure with a molecular deficiency >or=10%. While mechanical interactions between molecules and scanning probe tips had been pointed out as the major cause of scan-induced phase transformations in other SAM systems, electronic or electrostatic factors were thought to affect considerably the scan-induced ordering process in this SAM system. From comparison of surface molecular coverage between disordered and thermally ordered SAMs of PyC(12)SH, it was inferred that the disorder could be ascribed to both kinetic and thermodynamic factors. The kinetic barrier to the ordered phase was supposed to result from strong dipole-dipole interactions among the pyrrolyl endgroups.

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Surface-confined monomers on electrode surfaces Part 3. Electrochemical reactions and scanning probe microscopy investigations of ω-(N-pyrrolyl) alkanethiol self-assembled monolayers on gold

Cited by 33 publications

References 20 publications

Self‐Assembled Monolayers on Electrodes

Self‐Assembled Monolayers on Electrodes

Characterization of Organosulfur Molecular Monolayers on Au(111) using Scanning Tunneling Microscopy

Disorder–order phase change of ω-(N-pyrrolyl)alkanethiol self-assembled monolayers on gold induced by STM scans and thermal activation

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