Non-bonding interactions and internal dynamics in CH2F2⋯H2CO: a rotational and model calculations study

none7siThe 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) cm1.mixedQian Gou;Gang Feng;Luca Evangelisti;Montserrat Vallejo-López;Alberto Lesarri;Emilio J. Cocinero;Walther CaminatiQian Gou;Gang Feng;Luca Evangelisti;Montserrat Vallejo-López;Alberto Lesarri;Emilio J. Cocinero;Walther Caminat