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

Title: Accurate Lineshapes from Sub-1 cm-1 Resolution Sum Frequency Generation Vibrational Spectroscopy of α-Pinene at Room Temperature

Abstract

Room temperature sub-wavenumber high-resolution broadband sum frequency generation (HR-BB-SFG) spectra of the common terpene (+)-α-pinene reveal ten peaks in the C–H stretching region. The spectral resolution exceeds that of Fourier transform infrared, femtosecond stimulated Raman, and traditional BB-SFG and scanning SFG spectroscopy of the same molecule. Experiment and simulation show the spectral lineshapes to be accurate. Homogeneous vibrational decoherence lifetimes of up to 1.7 psec are assigned to specific oscillators and compare favorably to lifetimes computed from density functional tight binding molecular dynamics calculations, while phase-resolved spectra yield orientation information for them. We propose the new spectroscopy as an attractive alternative to time-resolved vibrational spectroscopy or heterodyne-detection schemes for studying vibrational energy relaxation and vibrational coherences in molecules.

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1184287
Report Number(s):
PNNL-SA-106190
47891; KP1704020
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry A, 119(8):1292-1302
Country of Publication:
United States
Language:
English
Subject:
Resolution; sum; frequency; generation; vibrational; spectra; Pinene; Environmental Molecular Sciences Laboratory

Citation Formats

Mifflin, Amanda L., Velarde Ruiz Esparza, Luis A., Ho, Junming, Psciuk, Brian, Negre, Christian, Ebben, Carlena J., Upshur, Mary Alice, Lu, Zhou, Strick, Benjamin, Thomson, Regan, Batista, Victor, Wang, Hongfei, and Geiger, Franz M.. Accurate Lineshapes from Sub-1 cm-1 Resolution Sum Frequency Generation Vibrational Spectroscopy of α-Pinene at Room Temperature. United States: N. p., 2015. Web. doi:10.1021/jp510700z.
Mifflin, Amanda L., Velarde Ruiz Esparza, Luis A., Ho, Junming, Psciuk, Brian, Negre, Christian, Ebben, Carlena J., Upshur, Mary Alice, Lu, Zhou, Strick, Benjamin, Thomson, Regan, Batista, Victor, Wang, Hongfei, & Geiger, Franz M.. Accurate Lineshapes from Sub-1 cm-1 Resolution Sum Frequency Generation Vibrational Spectroscopy of α-Pinene at Room Temperature. United States. doi:10.1021/jp510700z.
Mifflin, Amanda L., Velarde Ruiz Esparza, Luis A., Ho, Junming, Psciuk, Brian, Negre, Christian, Ebben, Carlena J., Upshur, Mary Alice, Lu, Zhou, Strick, Benjamin, Thomson, Regan, Batista, Victor, Wang, Hongfei, and Geiger, Franz M.. 2015. "Accurate Lineshapes from Sub-1 cm-1 Resolution Sum Frequency Generation Vibrational Spectroscopy of α-Pinene at Room Temperature". United States. doi:10.1021/jp510700z.
@article{osti_1184287,
title = {Accurate Lineshapes from Sub-1 cm-1 Resolution Sum Frequency Generation Vibrational Spectroscopy of α-Pinene at Room Temperature},
author = {Mifflin, Amanda L. and Velarde Ruiz Esparza, Luis A. and Ho, Junming and Psciuk, Brian and Negre, Christian and Ebben, Carlena J. and Upshur, Mary Alice and Lu, Zhou and Strick, Benjamin and Thomson, Regan and Batista, Victor and Wang, Hongfei and Geiger, Franz M.},
abstractNote = {Room temperature sub-wavenumber high-resolution broadband sum frequency generation (HR-BB-SFG) spectra of the common terpene (+)-α-pinene reveal ten peaks in the C–H stretching region. The spectral resolution exceeds that of Fourier transform infrared, femtosecond stimulated Raman, and traditional BB-SFG and scanning SFG spectroscopy of the same molecule. Experiment and simulation show the spectral lineshapes to be accurate. Homogeneous vibrational decoherence lifetimes of up to 1.7 psec are assigned to specific oscillators and compare favorably to lifetimes computed from density functional tight binding molecular dynamics calculations, while phase-resolved spectra yield orientation information for them. We propose the new spectroscopy as an attractive alternative to time-resolved vibrational spectroscopy or heterodyne-detection schemes for studying vibrational energy relaxation and vibrational coherences in molecules.},
doi = {10.1021/jp510700z},
journal = {Journal of Physical Chemistry A, 119(8):1292-1302},
number = ,
volume = ,
place = {United States},
year = 2015,
month = 2
}
  • The ability to achieve sub-wavenumber resolution (0.6 cm-1) and large signal-to-noise ratios in high-resolution broadband sum-frequency generation vibrational spectroscopy (HR-BB-SFG-VS) allows for the detailed SFG spectral lineshapes to be used in the unambiguous determination of fine spectral features. Changes in the structural spectroscopic phase in SFG-VS as a function of beam polarization and experimental geometry proved to be instrumental in the identification of an unexpected 2.78 +/- 0.07 cm-1 spectral splitting for two methyl groups at the vapor/dimethyl sulfoxide liquid interface, as well as in the determination of their orientational angles.
  • Even though in principle the frequency-domain and time-domain spectroscopic measurement should generate identical information for a given molecular system, inhomogeneous character of surface vibrations in the sum-frequency generation vibrational spectroscopy (SFG-VS) studies has only been studied with the time-domain SFGVS by mapping the decay of the vibrational polarization using ultrafast lasers, due to the lack of SFG vibrational spectra with high enough spectral resolution and accurate enough line shape. Here with recently developed high-resolution broadband SFG-VS (HR-BB-SFG-VS) we show that the inhomogeneous line shape can be obtained in the frequency-domain, for the anchoring CN stretch of the 4-n-octyl-4'-cyanobiphenyl (8CB) Langmuirmore » monolayer at the air-water interface, and that an excellent agreement with the time-domain SFG free-induction-decay (FID) results can be established. We found that the 8CB CN stretch spectrum consists of a single peak centered at 2234.00 + * 0.01 cm-1 with a total line width of 10.9 + - 0.3 cm-1 at half maximum. The Lorentzian contribution accounts only for 4:7 + -0:4 cm-1 to this width and the Gaussian (inhomogeneous) broadening for as much as 8:1+*0:2 cm-1. Polarization analysis of the -CN spectra showed that the -CN group is tilted 57 + - 2 degrees from the surface normal. The large heterogeneity in the -CN spectrum is tentatively attributed to the -CN group interactions with the interfacial water molecules penetrated/accomodated into the 8CB monolayer, a unique phenomenon for the nCB Langmuir monolayers reported previously.« less
  • Here we reported the first sub-wavenumber high-resolution broadband sum frequency generation vibrational spectroscopy (HR-BB-SFG-VS) study on both the C-H and O-H region spectra of crystalline cellulose. HR-BB-SFG-VS has about 10 times better resolution than the conventional scanning SFG-VS and is known to be able to measure the intrinsic spectral lineshape and to resolve much more spectral details. With HR-BB-SFG-VS, we found that in cellulose from different sources, including Avicel and cellulose crystals isolated from algae Valonia (Iα) and tunicates (Iβ), the spectral signatures in the OH regions were unique for different allomorphs, i.e. Iα and Iβ, while the spectral signaturesmore » in the C-H regions varied in all samples examined. Even though the origin of the different behaviors of the crystalline cellulose in the O-H and C-H vibrational frequency regions is yet to be correlated to the structure of cellulose, these results provided new spectroscopic methods and opportunities to classify and understand the basic crystalline structure, as well as variations, in polymorphism of the crystalline cellulose structure.« less
  • Both the C–H and O–H region spectra of crystalline cellulose were studied using the sub-wavenumber high-resolution broadband sum frequency generation vibrational spectroscopy (HR-BB-SFG-VS) for the first time. The resolution of HR-BB-SFG-VS is about 10-times better than conventional scanning SFG-VS and has the capability of measuring the intrinsic spectral lineshape and revealing many more spectral details. With HR-BB-SFG-VS, we found that in cellulose samples from different sources, including Avicel and cellulose crystals isolated from algae Valonia (Iα) and tunicates (Iβ), the spectral signatures in the O–H region were unique for the two allomorphs, i.e. Iα and Iβ, while the spectral signaturesmore » in the C–H regions varied in all samples examined. Even though the origin of the different spectral signatures of the crystalline cellulose in the O–H and C–H vibrational frequency regions are yet to be correlated to the structure of cellulose, these results lead to new spectroscopic methods and opportunities to classify and to understand the basic crystalline structures, as well as variations in polymorphism of the crystalline cellulose.« less