Microwave spectra and centrifugal distortion constants of formic acid containing 13C and 18O: Refinement of the harmonic force field and the molecular structure

Rotational Spectra of cis-HCOOH, trans-HCOOH, and trans-H13COOH

“…The 20 lines reported in that paper were included in the analysis of the present data. The starting point for the trans-H 13 COOH species was the publication of Davies et al (16), and the transitions in that paper were also included in the fits of the present data. Figure 4 shows a portion of the region scanned with the terahertz spectrometer, and the corresponding portion of the FTIR spectrum.…”

New High-Resolution Analysis of the ν7 and ν9 Fundamental Bands of trans-Formic Acid by Fourier Transform Infrared and Millimeter-Wave Spectroscopy

“…(18)(19)(20) and references therein). Formic acid possesses nine vibrational modes; a comprehensive vibrational study of this molecule was performed by Redington (21), who measured the vibrational frequencies of formic acid in a neon matrix for 24 different isotopic species.…”

“…Finally, the harmonic and anharmonic potential functions of this molecule were determined in Refs. (18,19,21,23).…”

The Vibrational State v5=1 of HCOOD

“…(2), 10.8 (MHz) 2 , while for the other six tested isotopic species it varies from 3.1 to 4.5 (MHz) 2 (3). Hence it could be expected that the v 5 = 1 vibrational state constants derived in Ref.…”