title: Pyridine-CF4: a molecule with a rotating cap.
abstract: The rotational spectrum of pyridine-CF4 has been investigated by molecular beam Fourier transform microwave spectroscopy in a supersonic expansion. The CF4 moiety is located as a cap over the pyridine nitrogen, and the two parts are freely rotating with respect to each other. For this reason, in a first approximation, in the m = 0 state only the pyridine ring is rotating along the a-axis, and the value of rotational constant A' is nearly the same of the constant A of isolated pyridine. The N···CCF4 distance is 3.372(1) Å. The dissociation energy has been estimated, from the centrifugal distortion, to be ca. 10 kJ/mol.
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna , Via Selmi 2, I-40126 Bologna, Italy.
authors.forename: Assimo
authors.initials: A
authors.lastname: Maris
authors.forename: Laura B
authors.initials: LB
authors.lastname: Favero
authors.forename: Biagio
authors.initials: B
authors.lastname: Velino
authors.forename: Walther
authors.initials: W
authors.lastname: Caminati