Vibrational sum frequency spectroscopic investigation of the azimuthal anisotropy and rotational dynamics of methyl-terminated silicon(111) surfaces

Sergey Malyk, Fadel Y. Shalhout, Leslie E. O'Leary, Nathan S Lewis, Alexander V. Benderskii

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Polarization-selected vibrational sum frequency generation spectroscopy (SFG) has been used to investigate the molecular orientation of methyl groups on CH3-terminated Si(111) surfaces. The symmetric and asymmetric C-H stretch modes of the surface-bound methyl group were observed by SFG. Both methyl stretches showed a pronounced azimuthal anisotropy of the 3-fold symmetry in registry with the signal from the Si(111) substrate, indicating that the propeller-like rotation of the methyl groups was hindered at room temperature. The difference in the SFG line widths for the CH3 asymmetric stretch that was observed for different polarization combinations (SPS and PPP for SFG, visible, and IR) indicated that the rotation proceeded on a 1-2 ps time scale, as compared to the ∼100 fs rotational dephasing of a free methyl rotor at room temperature.

Original languageEnglish
Pages (from-to)935-944
Number of pages10
JournalJournal of Physical Chemistry C
Volume117
Issue number2
DOIs
Publication statusPublished - Jan 17 2013

Fingerprint

Vibrational spectra
Silicon
Anisotropy
Spectroscopy
anisotropy
silicon
spectroscopy
Polarization
propellers
Molecular orientation
room temperature
Propellers
polarization
Linewidth
rotors
Rotors
Temperature
symmetry
Substrates

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Energy(all)

Cite this

Vibrational sum frequency spectroscopic investigation of the azimuthal anisotropy and rotational dynamics of methyl-terminated silicon(111) surfaces. / Malyk, Sergey; Shalhout, Fadel Y.; O'Leary, Leslie E.; Lewis, Nathan S; Benderskii, Alexander V.

In: Journal of Physical Chemistry C, Vol. 117, No. 2, 17.01.2013, p. 935-944.

Research output: Contribution to journalArticle

@article{54245804877d4959917eff32b210ae99,
title = "Vibrational sum frequency spectroscopic investigation of the azimuthal anisotropy and rotational dynamics of methyl-terminated silicon(111) surfaces",
abstract = "Polarization-selected vibrational sum frequency generation spectroscopy (SFG) has been used to investigate the molecular orientation of methyl groups on CH3-terminated Si(111) surfaces. The symmetric and asymmetric C-H stretch modes of the surface-bound methyl group were observed by SFG. Both methyl stretches showed a pronounced azimuthal anisotropy of the 3-fold symmetry in registry with the signal from the Si(111) substrate, indicating that the propeller-like rotation of the methyl groups was hindered at room temperature. The difference in the SFG line widths for the CH3 asymmetric stretch that was observed for different polarization combinations (SPS and PPP for SFG, visible, and IR) indicated that the rotation proceeded on a 1-2 ps time scale, as compared to the ∼100 fs rotational dephasing of a free methyl rotor at room temperature.",
author = "Sergey Malyk and Shalhout, {Fadel Y.} and O'Leary, {Leslie E.} and Lewis, {Nathan S} and Benderskii, {Alexander V.}",
year = "2013",
month = "1",
day = "17",
doi = "10.1021/jp3067298",
language = "English",
volume = "117",
pages = "935--944",
journal = "Journal of Physical Chemistry C",
issn = "1932-7447",
publisher = "American Chemical Society",
number = "2",

}

TY - JOUR

T1 - Vibrational sum frequency spectroscopic investigation of the azimuthal anisotropy and rotational dynamics of methyl-terminated silicon(111) surfaces

AU - Malyk, Sergey

AU - Shalhout, Fadel Y.

AU - O'Leary, Leslie E.

AU - Lewis, Nathan S

AU - Benderskii, Alexander V.

PY - 2013/1/17

Y1 - 2013/1/17

N2 - Polarization-selected vibrational sum frequency generation spectroscopy (SFG) has been used to investigate the molecular orientation of methyl groups on CH3-terminated Si(111) surfaces. The symmetric and asymmetric C-H stretch modes of the surface-bound methyl group were observed by SFG. Both methyl stretches showed a pronounced azimuthal anisotropy of the 3-fold symmetry in registry with the signal from the Si(111) substrate, indicating that the propeller-like rotation of the methyl groups was hindered at room temperature. The difference in the SFG line widths for the CH3 asymmetric stretch that was observed for different polarization combinations (SPS and PPP for SFG, visible, and IR) indicated that the rotation proceeded on a 1-2 ps time scale, as compared to the ∼100 fs rotational dephasing of a free methyl rotor at room temperature.

AB - Polarization-selected vibrational sum frequency generation spectroscopy (SFG) has been used to investigate the molecular orientation of methyl groups on CH3-terminated Si(111) surfaces. The symmetric and asymmetric C-H stretch modes of the surface-bound methyl group were observed by SFG. Both methyl stretches showed a pronounced azimuthal anisotropy of the 3-fold symmetry in registry with the signal from the Si(111) substrate, indicating that the propeller-like rotation of the methyl groups was hindered at room temperature. The difference in the SFG line widths for the CH3 asymmetric stretch that was observed for different polarization combinations (SPS and PPP for SFG, visible, and IR) indicated that the rotation proceeded on a 1-2 ps time scale, as compared to the ∼100 fs rotational dephasing of a free methyl rotor at room temperature.

UR - http://www.scopus.com/inward/record.url?scp=84872736628&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84872736628&partnerID=8YFLogxK

U2 - 10.1021/jp3067298

DO - 10.1021/jp3067298

M3 - Article

VL - 117

SP - 935

EP - 944

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

IS - 2

ER -