The ground states of 2-fluorophenol (2FPh) and 3-fluorophenol (3FPh) and their 13 C isotopologues were investigated using Fourier transform microwave (FTMW) spectroscopy in the range of 6 to 26 GHz. Two planar conformers were observed for 3FPh, corresponding to cis and trans orientations of OH relative to F, while only the cis conformer of 2FPh was detected.The rotational constants determined were used to derive substitution (rs) and effective ground state (r0) structures of the lowest energy conformer of each compound: cis-2FPh and trans-3FPh.Geometry optimization at the MP2/6-311++G(2d,2p) level provided equilibrium (re) structures which are in close agreement with the experimental parameters. The derived structures along with results from natural bond orbital (NBO) calculations provide evidence of an intramolecular interaction in cis-2FPh between the fluorine atom and OH moiety that stabilize this conformer by 0.72 kcal/mol. .

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The ground states of 2-fluorophenol (2-FPh) and 3-fluorophenol (3-FPh) were studied using Fourier transform microwave (FTMW) techniques to record their rotational spectra in the range of 6 to 26 GHz. Two planar conformers of similar energy were observed for 3-FPh (cis, trans) while only the lowest energy conformer (cis) of 2-FPh was observed due to the stabilizing effect of an intramolecular interaction between fluorine and OH. Rotational constants derived from spectra of the 13 C analogs, observed in natural abundance, were used to calculate the substitution (r s ) and effective ground state (r 0 ) parameters for cis-2-FPh and trans-3-FPh in order to study the effect of fluorination at sites along the benzene backbone. Geometry optimization at the MP2/6-311++G(2d,2p) level was used obtain the equilibrium (r e ) structures for comparison. Furthermore, natural bond order (NBO) calculations provided supporting information of a OH•••F interaction in cis-2-FPh.

Rotationally-resolved vibrational spectra of trimethlyene oxide (c-C 3 H6O) from 650 through 1200 cm −1 were recorded using far infrared synchrotron radiation at the Canadian Light Source with better than 0.001 cm −1 resolution. The observed bands correspond to at least eight different fundamental vibrations in this region. Due to the low frequency ring puckering motion, a the observed rovibrational pattern of each band is congested with hot-combination bands that originate in the first two excited ring puckering states (52.9 cm −1 , 142.6 cm −1 ). The ongoing analysis of the strong b-type bands corresponding to asymmetric in-plane CO stretching (ν 10 :1008 cm −1 ) b will be discussed along with the identification of allowed Coriolis interactions arising from nearby energy levels related to in-plane CC stretching (ν 9 : 940 cm −1 , ν 3 : 1033 cm −1 ). a G. Moruzzi et al., J. Mol. Spectrosc. 219, 152 (2003). b Bánhegyi et al. Spectrochim. Acta. 39A, 761 (1983).