THE ANILINE-WATER COMPLEX - ROTATIONAL SPECTRUM AND MOLECULAR-STRUCTURE

The rotational spectra of aniline-water and its O-18 isotopomer have b een studied in the microwave region between 3 and 26.5 GHz using a pul sed molecular beam FT microwave spectrometer. The spectra were describ ed in terms of a centrifugally distorted asymmetric rotor. Assuming a linear hydrogen N ... H-O bond and that the water molecule was located in the symmetry plane of aniline, two structures turned out to be pos sible. In structure (I) the free water proton is directed toward the a niline ring. In structure (II) the proton is bent away from it. Ab ini tio calculations indicate that only structure (I) is supported by the experimental results. (C) 1998 Academic Press.