title: Non-bonding interactions and internal dynamics in CH2F2···H2CO: a rotational and model calculations study.
abstract: The rotational spectra of three isotopologues of the 1 : 1 complex between difluoromethane and formaldehyde have been observed and assigned using pulsed jet Fourier transform microwave spectroscopy. The formaldehyde lies in the FCF plane of difluoromethane, linked through a C-H···F and a bifurcated CH2···O weak hydrogen bonds. The rotational transitions are split into two component lines with a relative intensity ratio of 1 : 3, due to the internal rotation of the formaldehyde moiety along its symmetry axis. The barrier to this motion has been estimated by using a flexible model to be V2 = 180(10) cm(-1).
authors.affiliation: Department of Chemistry, University of Bologna, Via Selmi 2, I-40126 Bologna, Italy.
authors.forename: Qian
authors.initials: Q
authors.lastname: Gou
authors.forename: Gang
authors.initials: G
authors.lastname: Feng
authors.forename: Luca
authors.initials: L
authors.lastname: Evangelisti
authors.forename: Montserrat
authors.initials: M
authors.lastname: Vallejo-López
authors.forename: Alberto
authors.initials: A
authors.lastname: Lesarri
authors.forename: Emilio J
authors.initials: EJ
authors.lastname: Cocinero
authors.forename: Walther
authors.initials: W
authors.lastname: Caminati