The Millimeter Wave Spectrum of the Weakly Bound Complex CH2=CHCNH2O: Structure, Dynamics and Implications for Astronomical Search

The Millimeter Wave Spectrum of the Weakly Bound Complex CH2=CHCNH2O: Structure, Dynamics and Implications for Astronomical Search 

Camilla Calabrese, Annalisa Vigorito, Assimo Maris, Sergio Mariotti, Pantea Fathi,  Wolf. D. Geppert, Sonia Melandri

 

The weakly bound 1:1 complex between acrylonitrile (CH2=CHCN) and water has been characterized spectroscopically in the millimeter wave range (59.6-74.4 GHz) using a Free Jet Absorption Millimeter Wave spectrometer. Precise values of the rotational and quartic centrifugal distortion constants have been obtained from the measured frequencies of the normal and isotopically substituted water moiety (DOH, DOD, H18OH). Structural parameters have been estimated from the rotational constants and their differences among isotopologues: the complex has a planar structure with the two subunits held together by a O-H···N (2.248 Å) and a C-H···O (2.533 Å) interaction. The ab initio intermolecular binding energy, obtained at the counterpoise corrected MP2/aug-cc-pVTZ level of calculation, is Δe=24.4 kJ mol-1.