15min:

N. R. WALKER, V. A. MIKHAILOV, S. J. HARRIS, F. J. ROBERTS AND A. C. LEGON, School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K..

A Balle-Flygare FT-MW spectrometer coupled to a laser ablation source has been used to measure the pure rotational spectra of H₂O-AgCl and H₃N-AgCl. Both molecules are generated via laser ablation (532 nm) of a metal rod in the presence of CCl₄, argon, a low partial pressure of H₂O or NH₃ and are stabilized by supersonic expansion. Rotational constants and centrifugal distortion constants have been measured for eight isotopologues of H₂O-AgCl with substitutions at the silver, chlorine, oxygen and hydrogen atoms. B _0 and C _0 have been independently determined for six isotopologues and the spectra are consistent with a linear arrangement of oxygen, silver and chlorine atoms. The structure is either C _2v planar at equilibrium or C _S pyramidal but with a low potential-energy barrier to planarity such that the v=0 and 1 states associated with the motion that inverts the configuration at the O atom are well separated. Preliminary data from a study of H₃N-AgCl will also be presented. Several transitions have been observed and tentatively assigned to hyperfine components of the 2₀₂-1₀₁, 3₀₃-2₀₂ and 4₀₄-3₀₃ transitions of H₃N-¹⁰⁷Ag³⁵Cl and H₃N-¹⁰⁹Ag³⁵Cl. These data are consistent with a C _3v structure.