Self-assembled oligo(phenylene-ethynylene) molecular electronic switch monolayers on gold

Structures and chemical stability

Joshua James Stapleton, Philipp Harder, Thomas A. Daniel, Michael D. Reinard, Yuxing Yao, David W. Price, James M. Tour, David L. Allara

Research output: Contribution to journalArticle

133 Citations (Scopus)

Abstract

Self-assembled monolayers (SAMs) of the nitro-substituted oligo(phenylene-ethynylene) (OPE) 4,4′-(diethynylphenyl)-2′-nitro-1-benzenethiolate on Au{111} were prepared, and the structures were characterized by multiple techniques, including infrared spectroscopy, ellipsometry, and X-ray photoelectron spectroscopy. Assembly of the nitro-OPE SAM, either via acidic hydrolysis of the thioacetate derivative or from the thiol in pure solvent, produces a well-ordered SAM with a (√3 × √3) superlattice structure and an average molecular tilt of 32-39° from the surface normal. In comparison, SAMs prepared from the unsubstituted OPE show the same lattice structure and a similar tilt of ∼33°. In contrast, when the nitro-OPE SAM is assembled by hydrolysis of the thioacetate derivative under basic conditions, extensive redox reactions arise in which oxidation of the S atoms occurs with accompaying reduction of -NO2 to -NH2, apparently via intermediates including -NH(OH), to form mixed composition SAMs typically containing ∼30% of the amino-substituted molecule. Further, the nitro-OPE SAM, regardless of the preparation method, shows significant chemical instability under storage in air and/or light exposure. Since the nitro-OPE molecule and molecules with related structures are of considerable interest for molecular electronics applications, these results indicate that extreme diligence must be used in designing conditions for the fabrication of devices utilizing these SAMs.

Original languageEnglish (US)
Pages (from-to)8245-8255
Number of pages11
JournalLangmuir
Volume19
Issue number20
DOIs
StatePublished - Sep 30 2003

Fingerprint

Molecular electronics
switching circuits
molecular electronics
Chemical stability
Self assembled monolayers
Gold
Monolayers
Switches
gold
hydrolysis
molecules
thiols
ellipsometry
assembly
infrared spectroscopy
photoelectron spectroscopy
Molecules
Hydrolysis
preparation
oxidation

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

Cite this

Stapleton, Joshua James ; Harder, Philipp ; Daniel, Thomas A. ; Reinard, Michael D. ; Yao, Yuxing ; Price, David W. ; Tour, James M. ; Allara, David L. / Self-assembled oligo(phenylene-ethynylene) molecular electronic switch monolayers on gold : Structures and chemical stability. In: Langmuir. 2003 ; Vol. 19, No. 20. pp. 8245-8255.
@article{da13b69203974bfbbd61a38c81f56a7b,
title = "Self-assembled oligo(phenylene-ethynylene) molecular electronic switch monolayers on gold: Structures and chemical stability",
abstract = "Self-assembled monolayers (SAMs) of the nitro-substituted oligo(phenylene-ethynylene) (OPE) 4,4′-(diethynylphenyl)-2′-nitro-1-benzenethiolate on Au{111} were prepared, and the structures were characterized by multiple techniques, including infrared spectroscopy, ellipsometry, and X-ray photoelectron spectroscopy. Assembly of the nitro-OPE SAM, either via acidic hydrolysis of the thioacetate derivative or from the thiol in pure solvent, produces a well-ordered SAM with a (√3 × √3) superlattice structure and an average molecular tilt of 32-39° from the surface normal. In comparison, SAMs prepared from the unsubstituted OPE show the same lattice structure and a similar tilt of ∼33°. In contrast, when the nitro-OPE SAM is assembled by hydrolysis of the thioacetate derivative under basic conditions, extensive redox reactions arise in which oxidation of the S atoms occurs with accompaying reduction of -NO2 to -NH2, apparently via intermediates including -NH(OH), to form mixed composition SAMs typically containing ∼30{\%} of the amino-substituted molecule. Further, the nitro-OPE SAM, regardless of the preparation method, shows significant chemical instability under storage in air and/or light exposure. Since the nitro-OPE molecule and molecules with related structures are of considerable interest for molecular electronics applications, these results indicate that extreme diligence must be used in designing conditions for the fabrication of devices utilizing these SAMs.",
author = "Stapleton, {Joshua James} and Philipp Harder and Daniel, {Thomas A.} and Reinard, {Michael D.} and Yuxing Yao and Price, {David W.} and Tour, {James M.} and Allara, {David L.}",
year = "2003",
month = "9",
day = "30",
doi = "10.1021/la035172z",
language = "English (US)",
volume = "19",
pages = "8245--8255",
journal = "Langmuir",
issn = "0743-7463",
publisher = "American Chemical Society",
number = "20",

}

Stapleton, JJ, Harder, P, Daniel, TA, Reinard, MD, Yao, Y, Price, DW, Tour, JM & Allara, DL 2003, 'Self-assembled oligo(phenylene-ethynylene) molecular electronic switch monolayers on gold: Structures and chemical stability', Langmuir, vol. 19, no. 20, pp. 8245-8255. https://doi.org/10.1021/la035172z

Self-assembled oligo(phenylene-ethynylene) molecular electronic switch monolayers on gold : Structures and chemical stability. / Stapleton, Joshua James; Harder, Philipp; Daniel, Thomas A.; Reinard, Michael D.; Yao, Yuxing; Price, David W.; Tour, James M.; Allara, David L.

In: Langmuir, Vol. 19, No. 20, 30.09.2003, p. 8245-8255.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Self-assembled oligo(phenylene-ethynylene) molecular electronic switch monolayers on gold

T2 - Structures and chemical stability

AU - Stapleton, Joshua James

AU - Harder, Philipp

AU - Daniel, Thomas A.

AU - Reinard, Michael D.

AU - Yao, Yuxing

AU - Price, David W.

AU - Tour, James M.

AU - Allara, David L.

PY - 2003/9/30

Y1 - 2003/9/30

N2 - Self-assembled monolayers (SAMs) of the nitro-substituted oligo(phenylene-ethynylene) (OPE) 4,4′-(diethynylphenyl)-2′-nitro-1-benzenethiolate on Au{111} were prepared, and the structures were characterized by multiple techniques, including infrared spectroscopy, ellipsometry, and X-ray photoelectron spectroscopy. Assembly of the nitro-OPE SAM, either via acidic hydrolysis of the thioacetate derivative or from the thiol in pure solvent, produces a well-ordered SAM with a (√3 × √3) superlattice structure and an average molecular tilt of 32-39° from the surface normal. In comparison, SAMs prepared from the unsubstituted OPE show the same lattice structure and a similar tilt of ∼33°. In contrast, when the nitro-OPE SAM is assembled by hydrolysis of the thioacetate derivative under basic conditions, extensive redox reactions arise in which oxidation of the S atoms occurs with accompaying reduction of -NO2 to -NH2, apparently via intermediates including -NH(OH), to form mixed composition SAMs typically containing ∼30% of the amino-substituted molecule. Further, the nitro-OPE SAM, regardless of the preparation method, shows significant chemical instability under storage in air and/or light exposure. Since the nitro-OPE molecule and molecules with related structures are of considerable interest for molecular electronics applications, these results indicate that extreme diligence must be used in designing conditions for the fabrication of devices utilizing these SAMs.

AB - Self-assembled monolayers (SAMs) of the nitro-substituted oligo(phenylene-ethynylene) (OPE) 4,4′-(diethynylphenyl)-2′-nitro-1-benzenethiolate on Au{111} were prepared, and the structures were characterized by multiple techniques, including infrared spectroscopy, ellipsometry, and X-ray photoelectron spectroscopy. Assembly of the nitro-OPE SAM, either via acidic hydrolysis of the thioacetate derivative or from the thiol in pure solvent, produces a well-ordered SAM with a (√3 × √3) superlattice structure and an average molecular tilt of 32-39° from the surface normal. In comparison, SAMs prepared from the unsubstituted OPE show the same lattice structure and a similar tilt of ∼33°. In contrast, when the nitro-OPE SAM is assembled by hydrolysis of the thioacetate derivative under basic conditions, extensive redox reactions arise in which oxidation of the S atoms occurs with accompaying reduction of -NO2 to -NH2, apparently via intermediates including -NH(OH), to form mixed composition SAMs typically containing ∼30% of the amino-substituted molecule. Further, the nitro-OPE SAM, regardless of the preparation method, shows significant chemical instability under storage in air and/or light exposure. Since the nitro-OPE molecule and molecules with related structures are of considerable interest for molecular electronics applications, these results indicate that extreme diligence must be used in designing conditions for the fabrication of devices utilizing these SAMs.

UR - http://www.scopus.com/inward/record.url?scp=0141888178&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0141888178&partnerID=8YFLogxK

U2 - 10.1021/la035172z

DO - 10.1021/la035172z

M3 - Article

VL - 19

SP - 8245

EP - 8255

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 20

ER -