Kr-Cl stretching vibration of HKrCl:: Matrix-isolation and anharmonic ab initio study

The Kr-Cl stretching vibration of HKrCl molecule is studied. The absorption shows Cl-35 and Cl-37 isotopic splitting due to natural abundance of the Cl isotopes. The observed Kr-Cl stretching vibrations of the HKrCl are at 253.1 (Cl-35) and 248.3 cm(-1) (Cl-37). Experimentally, deuteration of the HKrCl does not cause a shift of the Kr-Cl stretching frequency. In addition to the Kr-Cl stretching mode, the bending mode of DKrCl is observed at 397.7 cm(-1). The vibrational analysis suggests that the Kr-Cl bond shows some covalent character in addition to the ionic. Anharmonic ab initio calculations are employed to verify the vibrational properties of various isotopologues of HKrCl. (C) 2003 American Institute of Physics.