title: Tunnelling motion of HF between the two oxygen lone pairs in the dimethyl ether-hydrogen fluoride complex: a pure rotational study.
abstract: The rotational spectrum of the dimethyl ether-hydrogen fluoride complex was assigned by millimetre-wave free-jet absorption spectroscopy. Fine details of the spectrum were resolved by FT microwave molecular-beam spectroscopy. The HF group acts as a proton donor and tunnels at a rate of 44178.2(7) MHz between the two oxygen lone pairs, which corresponds to an inversion barrier of 0.17 (1) kcal mol-1. The barrier to internal rotation of the two methyl groups is about 25% lower relative to the isolated ether.
authors.affiliation: Dipartimento di Chimica G. Ciamician dell'Università Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ottaviani
authors.forename: Walther
authors.initials: W
authors.lastname: Caminati
authors.forename: Biagio
authors.initials: B
authors.lastname: Velino
authors.forename: Susana
authors.initials: S
authors.lastname: Blanco
authors.forename: Alberto
authors.initials: A
authors.lastname: Lesarri
authors.forename: Juan C
authors.initials: JC
authors.lastname: López
authors.forename: José L
authors.initials: JL
authors.lastname: Alonso