title: Shapes and noncovalent interactions of oligomers: the rotational spectrum of the difluoromethane trimer.
abstract: The trimer of difluoromethane, (CH2F2)3, has been characterized by supersonic jet Fourier transform microwave spectroscopy. The rotational spectrum displays all types (mu(a), mu(b), and mu(c)) of transitions, showing that the adduct does not possess any element of molecular symmetry. The investigation of the three 13C species in natural abundance indicates that the three carbon atoms form a triangle where the C-C distances are 3.648(2), 3.825(8), and 3.942(6) A, respectively. The three subunits are held together by nine CH...F weak hydrogen bonds.
authors.affiliation: Dipartimento di Chimica G. Ciamician dell'Università, Via Selmi 2, I-40126 Bologna, Italy.
authors.forename: Susana
authors.initials: S
authors.lastname: Blanco
authors.forename: Sonia
authors.initials: S
authors.lastname: Melandri
authors.forename: Paolo
authors.initials: P
authors.lastname: Ottaviani
authors.forename: Walther
authors.initials: W
authors.lastname: Caminati