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Title: Formation and detection of metastable formic acid in a supersonic expansion: High resolution infrared spectroscopy of the jet-cooled cis-HCOOH conformer

Journal Article · · Journal of Chemical Physics
DOI: https://doi.org/10.1063/5.0093401 · OSTI ID:1924522
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]; ORCiD logo [1]
  1. Univ. of Colorado, Boulder, CO (United States); National Inst. of Standards and Technology (NIST), Boulder, CO (United States)
  2. Univ. of Colorado, Boulder, CO (United States); National Inst. of Standards and Technology (NIST), Boulder, CO (United States); ColdQuanta, Boulder, CO (United States)
+ Show Author Affiliations

High-resolution direct absorption infrared spectra of metastable cis-formic acid (HCOOH) trapped in a cis-well resonance behind a 15 kcal/mol barrier are reported for the first time, with the energetically unstable conformer produced in a supersonic slit plasma expansion of trans-formic acid/H2 mixtures. We present a detailed high-resolution rovibrational analysis for cis-formic acid species in the OH stretch (ν1) fundamental, providing first precision vibrational band origin, rotational constants, and term values, which in conjunction with ab initio calculations at the couple-cluster with single, double, and perturbative triple [CCSD(T)]/ANOn (n = 0, 1, 2) level support the experimental assignments and establish critical points on the potential energy surface for internal rotor trans-to-cis isomerization. Relative intensities for a- and b-type transitions observed in the spectra permit the transition dipole moment components to be determined in the body fixed frame and prove to be in good agreement with ab initio CCSD(T) theoretical estimates but in poor agreement with simple bond-dipole predictions. As a result, the observed signal dependence on H2 in the discharge suggests the presence of a novel H atom radical chemical mechanism for strongly endothermic “up-hill” internal rotor isomerization between trans- and cis-formic acid conformers.

Research Organization:
Univ. of Colorado, Boulder, CO (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE
Contributing Organization:
NSF (PHYS), NIST NRC
Grant/Contract Number:
SC0002123
OSTI ID:
1924522
Journal Information:
Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 20 Vol. 156; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (29)

The role of databases in support of computational chemistry calculations journal October 1996
Rotational Spectra of cis-HCOOH, trans-HCOOH, and trans-H13COOH journal December 2002
New High-Resolution Analysis of the ν7 and ν9 Fundamental Bands of trans-Formic Acid by Fourier Transform Infrared and Millimeter-Wave Spectroscopy journal December 2002
ν7 and ν9 bands of formic acid near 16 μm journal December 1979
Sub-Doppler laser-Stark and high-resolution Fourier transform spectroscopy of the ν3 band of formic acid journal February 1987
The high-resolution infrared spectrum of the ν 3 + ν 5 combination band of jet-cooled propyne journal September 2017
PGOPHER: A program for simulating rotational, vibrational and electronic spectra journal January 2017
High resolution FTIR spectra of the ν9 vibrational band of cis-rotamers HCOOH and H13COOH journal August 2006
Concentration modulation spectroscopy with a pulsed slit supersonic discharge expansion source journal August 2001
Basis Set Exchange:  A Community Database for Computational Sciences journal March 2007
Kinetic and mechanistic study of the hydroxyl + formic acid reaction journal June 1985
IR Spectrum of the Other Rotamer of Formic Acid, cis -HCOOH journal December 1997
Sub-Doppler Spectroscopy of the trans -HOCO Radical in the OH Stretching Mode journal June 2013
Stretching of cis -formic acid: warm-up and cool-down as molecular work-out journal January 2019
Trans-cis molecular photoswitching in interstellar space journal November 2016
Ice absorption features in the 5-8 μ m region toward embedded protostars journal September 2001
Slit pulsed valve for generation of long‐path‐length supersonic expansions journal May 1987
Stabilization and precise calibration of a continuous‐wave difference frequency spectrometer by use of a simple transfer cavity journal January 1994
High‐resolution laser spectroscopy of the ν 3 vibration‐rotation band of HCOOH journal July 1982
General contraction of Gaussian basis sets. I. Atomic natural orbitals for first‐ and second‐row atoms journal April 1987
High-resolution infrared spectroscopy of jet cooled trans -deuteroxycarbonyl ( trans -DOCO) radical journal May 2019
Coupled-cluster techniques for computational chemistry: The CFOUR program package journal June 2020
Treatment of Fermi resonance effects on transition moments in vibrational perturbation theory journal January 2007
Microwave Detection of Interstellar Formic Acid journal January 1971
Observations of Formic Acid in Hot Molecular Cores journal May 2001
The Hot Core around the Low-Mass Protostar IRAS 16293-2422: Scoundrels Rule! journal July 2003
DISCOVERY OF THE METHOXY RADICAL, CH 3 O, TOWARD B1: DUST GRAIN AND GAS-PHASE CHEMISTRY IN COLD DARK CLOUDS journal October 2012
HOCO formation in astrochemical environments by radical-induced H-abstraction from formic acid journal September 2018
The Other Rotamer of Formic Acid, cis-HCOOH1 journal September 1976

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Ab-initio methods
Acids
Infrared spectroscopy
Isomerization
Plasma expansion
Potential energy surfaces
Rotational dynamics
Rotational spectra
Transition moment
Vibrational states