Infrared Spectroscopy and Monte Carlo Simulations of Doped Helium Nanodroplets

Helium nanodroplets isolation has been used to isolate the norm-, sec-, iso-, and tert-butyl radicals in a minimally perturbative environment. The infrared spectra of these radicals were gathered in the CH stretching region of 2750−3125 cm−¹. These spectra represent the first high-resolution spectra of s-butyl radical. The spectra of all butyl radicals were compared to VPT2+K computed spectra for the assignment of vibrational bands. These experimental spectra were also used as a comparison to local mode computed spectra to evaluate the extensibility of this computational method to larger hydrocarbon radicals. Monte Carlo electrostatic deflection simulations of droplets doped with oligomers of hydrogen cyanide were carried out. These simulations indicated the ability of static, inhomogenous electric fields to deflect a beam of doped droplets in a size-specific manner. This indicates that construction of an instrument to separate a beam of droplets by size and probe droplet-size dependent effects on the dopant molecules is feasible.