Infrared spectroscopy and structures of Ar[sub n]–HF in liquid helium nanodroplets.

Infrared spectra are reported for Ar[sub n]–HF complexes up to the closing of the first solvent shell. These complexes were grown in superfluid helium droplets, leading to the formation of multiple isomers for n>3. The vibrational frequency shifts associated with the HF stretch are in excellent agreement with previous theoretical calculations. The relative abundances of the various isomers is found to be dependent upon the order of pick-up of the HF and argon. When HF is added to the droplets first the isomers corresponding to the solvated HF are produced in high abundance. Growth of the argon cluster prior to addition of the HF leads to the latter being on the “surface” of the argon cluster. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]