U. Happek et al., RELAXATION OF THE CN- STRETCHING VIBRATION IN SILVER-HALIDES - THE ROLE OF ACCEPTING MODES, Physical review letters, 72(24), 1994, pp. 3903-3906
The vibrational relaxation of CN- in AgCl and AgBr is found to be 1000
times faster than in the potassium, rubidium, and cesium halides, mea
sured previously. We demonstrate that high-frequency local modes are t
he source of this difference, which also explains the short times foun
d earlier for CN- in the sodium halides. An energy gap law fits all of
the data, with the highest frequency bulk or localized phonon as the
accepting mode. Extrapolating this law down to a single accepting mode
, we obtain a subnanosecond lifetime, in agreement with previous measu
rements of CN- in aqueous solution.