title: Complementary cavity-enhanced spectrometers to investigate the OH + CH combination band in trans-formic acid.
abstract: We have used continuous-wave cavity ring-down and femto-Fourier transform-cavity-enhanced absorption spectrometers to record the spectrum of the OH-stretching + CH-stretching (ν1 + ν2) combination band in trans-formic acid, with origin close to 6507 cm(-1). They, respectively, allowed resolving and simplifying the rotational structure of the band near its origin under jet-cooled conditions (Trot = 10 K) and highlighting the overview of the band under room temperature conditions. The stronger B-type and weaker A-type subbands close to the band origin could be assigned, as well as the main B-type Q branches. The high-resolution analysis was hindered by numerous, severe perturbations. Rotational constants are reported with, however, limited physical meaning. The ν1 + ν2 transition moment is estimated from relative intensities to be 24° away from the principal b-axis of inertia.
authors.affiliation: Service de Chimie quantique et Photophysique, CP 160/09, Faculté des Sciences, Université libre de Bruxelles, Ave. F.D. Roosevelt, Brussels B-1050, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Golebiowski
authors.affiliation: Service de Chimie quantique et Photophysique, CP 160/09, Faculté des Sciences, Université libre de Bruxelles, Ave. F.D. Roosevelt, Brussels B-1050, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Földes
authors.affiliation: Service de Chimie quantique et Photophysique, CP 160/09, Faculté des Sciences, Université libre de Bruxelles, Ave. F.D. Roosevelt, Brussels B-1050, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Vanfleteren
authors.affiliation: Service de Chimie quantique et Photophysique, CP 160/09, Faculté des Sciences, Université libre de Bruxelles, Ave. F.D. Roosevelt, Brussels B-1050, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Herman
authors.affiliation: Laboratoire Interuniversitaire des Systèmes Atmosphériques, LISA-UMR7583, CNRS/ Université Paris Est Creteil and Université Paris 7 Diderot, Institut Paul Simon Laplace, 61 Ave. du Général de Gaulle, 94010 Creteil cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Perrin