title: Microwave measurements of the tropolone-formic acid doubly hydrogen bonded dimer.
abstract: The microwave spectrum was measured for the doubly hydrogen bonded dimer formed between tropolone and formic acid. The predicted symmetry of this dimer was C2v(M), and it was expected that the concerted proton tunneling motion would be observed. After measuring 25 a- and b-type rotational transitions, no splittings which could be associated with a concerted double proton tunneling motion were observed. The calculated barrier to the proton tunneling motion is near 15,000 cm(-1), which would likely make the tunneling frequencies too small to observe in the microwave spectra. The rotational and centrifugal distortion constants determined from the measured transitions were A = 2180.7186(98) MHz, B = 470.873 90(25) MHz, C = 387.689 84(22) MHz, DJ = 0.0100(14) kHz, DJK = 0.102(28) kHz, and DK = 13.2(81) kHz. The B3LYP/aug-cc-pVTZ calculated rotational constants were within 1% of the experimentally determined values.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Pejlovas
authors.affiliation: Department of Chemistry, University of Texas Rio Grande Valley, Brownsville, Texas 78520, USA.
authors.forename: Agapito
authors.initials: A
authors.lastname: Serrato
authors.affiliation: Department of Chemistry, University of Texas Rio Grande Valley, Brownsville, Texas 78520, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Kukolich