TY - JOUR
T1 - Gas phase measurements of mono-fluoro-benzoic acids and the dimer of 3-fluoro-benzoic acid
AU - Daly, Adam M.
AU - Carey, Spencer J.
AU - Pejlovas, Aaron M.
AU - Li, Kexin
AU - Kang, Lu
AU - Kukolich, Stephen G.
N1 - Publisher Copyright:
© 2015 AIP Publishing LLC.
PY - 2015/4/14
Y1 - 2015/4/14
N2 - The microwave spectrum of the mono-fluoro-benzoic acids, 2-fluoro-, 3-fluoro-, and 4-fluoro-benzoic acid have been measured in the frequency range of 4-14 GHz using a pulsed beam Fourier transform microwave spectrometer. Measured rotational transition lines were assigned and fit using a rigid rotor Hamiltonian. Assignments were made for 3 conformers of 2-fluorobenzoic acid, 2 conformers of 3-fluorobenzoic acid, and 1 conformer of 4-fluorobenzoic acid. Additionally, the gas phase homodimer of 3-fluorobenzoic acid was detected, and the spectra showed evidence of proton tunneling. Experimental rotational constants are A(0+) = 1151.8(5), B(0+) = 100.3(5), C(0+) = 87.64(3) MHz and A(0-) = 1152.2(5), B(0-) = 100.7(5), C(0-) = 88.85(3) MHz for the two ground vibrational states split by the proton tunneling motion. The tunneling splitting (ΔE) is approximately 560 MHz. This homodimer appears to be the largest carboxylic acid dimer observed with F-T microwave spectroscopy.
AB - The microwave spectrum of the mono-fluoro-benzoic acids, 2-fluoro-, 3-fluoro-, and 4-fluoro-benzoic acid have been measured in the frequency range of 4-14 GHz using a pulsed beam Fourier transform microwave spectrometer. Measured rotational transition lines were assigned and fit using a rigid rotor Hamiltonian. Assignments were made for 3 conformers of 2-fluorobenzoic acid, 2 conformers of 3-fluorobenzoic acid, and 1 conformer of 4-fluorobenzoic acid. Additionally, the gas phase homodimer of 3-fluorobenzoic acid was detected, and the spectra showed evidence of proton tunneling. Experimental rotational constants are A(0+) = 1151.8(5), B(0+) = 100.3(5), C(0+) = 87.64(3) MHz and A(0-) = 1152.2(5), B(0-) = 100.7(5), C(0-) = 88.85(3) MHz for the two ground vibrational states split by the proton tunneling motion. The tunneling splitting (ΔE) is approximately 560 MHz. This homodimer appears to be the largest carboxylic acid dimer observed with F-T microwave spectroscopy.
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U2 - 10.1063/1.4917031
DO - 10.1063/1.4917031
M3 - Article
AN - SCOPUS:84927604489
SN - 0021-9606
VL - 142
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 14
M1 - 144303
ER -