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DOES WATER PREFER TO DONATE A PROTON TO AN F OR TO a Cl ATOM? - A ROTATIONAL STUDY OF CH₃CHClF...H₂O.

GANG FENG, LUCA EVANGELISTI AND W. CAMINATI, Dipartimento di Chimica "G. Ciamician" dell'Università, Via Selmi 2, I-40126 Bologna, Italy; LAURA B. FAVERO, Istituto per lo Studio dei Materiali Nanostrutturati (ISMN, Sezione di Bologna), CNR, Via Gobetti 101, I-40129 Bologna, Italy; JENS-UWE GRABOW, Lehrgebiet Physikalische Chemie A, Institut für Physikalische Chemie und Elektrochemie, Universtät Hannover, Callinstr. 3A, D-30167 Hannover, Germany; ZHINING XIA, Chemistry and Chemistry Engineering College, Chongqing University, Chongqing, 400030, P. R. China.

We measured the molecular beam Fourier transform microwave spectra of six isotopologues of the 1:1 adduct of CH₃CHClF with water. The water prefers to form an O-H...F rather than an O-H...Cl hydrogen bond. This is exactly the contrary of what observed in the chlorofluoromethane-water adduct, where a O-H...Cl link was formed . Besides the rotational constants, the quadrupole coupling constants of the chlorine atom have been determined. In addition, information on the internal dynamics has been obtained.