skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Thiophene Derivatives on Gold and Molecular Dissociation Processes

Abstract

We report a systematic study of thiophene derivatives on gold surfaces. These molecules are of interest in molecular electronics, and the characracteristics of the thiophene–electrode interface in devices needs to be understood as it affects electron transport characteristics. Some experiments indicated S–C bond scission in contact with metals resulting in disruption of the π-electron system that affects charge transport, which would also be affected by presence of split-off chemisorbed sulfur. We explored this dissociation aspect by photoemission for the case of monocrystalline Au(111) surfaces and Au films grown on mica for a series of polythiophenes molecules (nT, n = 1–4, 6) as well as for α,ω-diquaterthiophene (DH4T) and dihexylsexithiophene (DH6T). The S 2p X-ray photoelectron spectroscopy peaks are found to have complex line shapes corresponding to S atoms with different core level binding energies (CLBE). Density functional theory calculations of adsorption energies and CLBEs were performed for various adsorption configurations of thiophene on a perfect Au(111) plane and for comparison, calculations were also performed for bithiophene, terthiophene, alkenethiol, alkenethiol chain, and a broken thiophene related metallocycle, incorporating an Au adatom and an S atom. On the basis of these results we relate the different contributions to the S 2p peakmore » to intact molecules on different adsorption sites and broken molecules. Calculations in particular show that the CLBEs for intact thiophene (1T) can be the same as for the alkene and alkanethiol cases as opposed to usual assumptions in the literature. The existence of intact thiophenes is confirmed by the presence of clear π resonance peaks in the near edge X-ray fine structure (NEXAFS) spectra. Spontaneous dissociation appears to a variable extent in different samples, and we tentatively relate this to the presence of a more or less large number of steps and defects sites. X-ray induced beam damage was investigated for 1T and 3T using an intense synchrotron beam of 260 eV photons, and showed changes in the S 2p spectra related to S–C bond scission.« less

Authors:
 [1];  [2];  [3];  [4]; ORCiD logo [5]; ORCiD logo [2]; ORCiD logo [1]
  1. Institut des Sciences Moléculaires d’Orsay, UMR 8214 CNRS, Université Paris Sud, Université Paris-Saclay, bât 520, F-91405 Orsay, France
  2. Department of Physics, University of Central Florida, Orlando, Florida 32816-2385, United States
  3. Institut des Sciences Moléculaires d’Orsay, UMR 8214 CNRS, Université Paris Sud, Université Paris-Saclay, bât 520, F-91405 Orsay, France; Synchrotron Soleil, L’Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette CEDEX F-91192, France
  4. Institut de Chimie Moléculaire et Matériaux d’Orsay, CNRS, Université Paris Sud, Orsay France
  5. Synchrotron Soleil, L’Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette CEDEX F-91192, France
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory-National Energy Research Scientific Computing Center
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1483384
Grant/Contract Number:  
FG02-11ER16243; SC0007045
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 121; Journal Issue: 50; Journal ID: ISSN 1932-7447
Country of Publication:
United States
Language:
English

Citation Formats

Jiang, Tingming, Malone, Walter, Tong, Yongfeng, Dragoe, Diana, Bendounan, Azzedine, Kara, Abdelkader, and Esaulov, Vladimir A. Thiophene Derivatives on Gold and Molecular Dissociation Processes. United States: N. p., 2017. Web. doi:10.1021/acs.jpcc.7b08006.
Jiang, Tingming, Malone, Walter, Tong, Yongfeng, Dragoe, Diana, Bendounan, Azzedine, Kara, Abdelkader, & Esaulov, Vladimir A. Thiophene Derivatives on Gold and Molecular Dissociation Processes. United States. doi:10.1021/acs.jpcc.7b08006.
Jiang, Tingming, Malone, Walter, Tong, Yongfeng, Dragoe, Diana, Bendounan, Azzedine, Kara, Abdelkader, and Esaulov, Vladimir A. Tue . "Thiophene Derivatives on Gold and Molecular Dissociation Processes". United States. doi:10.1021/acs.jpcc.7b08006. https://www.osti.gov/servlets/purl/1483384.
@article{osti_1483384,
title = {Thiophene Derivatives on Gold and Molecular Dissociation Processes},
author = {Jiang, Tingming and Malone, Walter and Tong, Yongfeng and Dragoe, Diana and Bendounan, Azzedine and Kara, Abdelkader and Esaulov, Vladimir A.},
abstractNote = {We report a systematic study of thiophene derivatives on gold surfaces. These molecules are of interest in molecular electronics, and the characracteristics of the thiophene–electrode interface in devices needs to be understood as it affects electron transport characteristics. Some experiments indicated S–C bond scission in contact with metals resulting in disruption of the π-electron system that affects charge transport, which would also be affected by presence of split-off chemisorbed sulfur. We explored this dissociation aspect by photoemission for the case of monocrystalline Au(111) surfaces and Au films grown on mica for a series of polythiophenes molecules (nT, n = 1–4, 6) as well as for α,ω-diquaterthiophene (DH4T) and dihexylsexithiophene (DH6T). The S 2p X-ray photoelectron spectroscopy peaks are found to have complex line shapes corresponding to S atoms with different core level binding energies (CLBE). Density functional theory calculations of adsorption energies and CLBEs were performed for various adsorption configurations of thiophene on a perfect Au(111) plane and for comparison, calculations were also performed for bithiophene, terthiophene, alkenethiol, alkenethiol chain, and a broken thiophene related metallocycle, incorporating an Au adatom and an S atom. On the basis of these results we relate the different contributions to the S 2p peak to intact molecules on different adsorption sites and broken molecules. Calculations in particular show that the CLBEs for intact thiophene (1T) can be the same as for the alkene and alkanethiol cases as opposed to usual assumptions in the literature. The existence of intact thiophenes is confirmed by the presence of clear π resonance peaks in the near edge X-ray fine structure (NEXAFS) spectra. Spontaneous dissociation appears to a variable extent in different samples, and we tentatively relate this to the presence of a more or less large number of steps and defects sites. X-ray induced beam damage was investigated for 1T and 3T using an intense synchrotron beam of 260 eV photons, and showed changes in the S 2p spectra related to S–C bond scission.},
doi = {10.1021/acs.jpcc.7b08006},
journal = {Journal of Physical Chemistry. C},
number = 50,
volume = 121,
place = {United States},
year = {2017},
month = {12}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share: