The rotational spectrum of the pyridine-hydrogen fluoride complex

Abstract

Rotational spectra of two isotopomers of the pyridine-hydrogen fluoride complex were observed by using a pulsed-nozzle, FT microwave spectrometer. The constants A 0, B 0, C 0, Δ JK , Δ JK , δ J , δ K , x( 14 N) were determined for both isotopomers from analysis of the spectra. The complex is assigned C 2v symmetry, with the HF molecule lying along the C 2 axis of the C 5H 5N subunit. The distance r( Ntctdot;F) = 2.609(5) A ̊ was determined by fitting the rotational constants under the assumption of unperturbed monomer geometries, and the intermolecular stretching force constant k σ = 27.0(3) N m −1 was calculated from the distortion constant Δ J . The properties of a series of complexes Btctdot;HF, where B is a nitrogen-containing Lewis base, are compared.