Fast Beam Translational Spectroscopy

Synopsis:

This project uses photofragment translational spectroscopy to investigate photodissociation dynamics of free radical species upon the absorption of a UV photon. The fast radical beam machine operates by producing an anionic precursor from which an electron is detached to make neutral free radicals in their ground vibrational states. These radicals are subsequently dissociated and the photofragments are collected in coincidence using a hexanode delay-line detector which records both time and position information of all photofragments produced from a given dissociating radical.

Position and arrival time of the photoproducts allows for the generation of mass, translational energy, and angular distributions. Using these respective distributions, the photofragments are identified, and the dynamics leading to their formation can be determined.

Recent Molecules Studied:

Alkyl Peroxy Radicals: t-C₄H₉OO, CH₃OO, C₂H₅OO

Alkyl Perthiyl Radicals: t-C₄H₉SS, CH₃SS

i-methylvinoxy: CH₃COCH₂

Project members:

Steve Saric

Recent publications:

♦ "Photodissociation of iso-Propoxy (i-C₃H₇O) Radical at 248 nm" E. N. Sullivan, S. Saric, D. M. Neumark Phys. Chem. Chem. Phys. (2020). pdf

♦ "Photodissociation dynamics of the tert-butyl perthiyl radical" B. Nichols, E. N. Sullivan, D. M. Neumark J. Chem. Phys. 152, 244301 (2020). pdf

♦ "Multiphoton dissociation dynamics of the indenyl radical at 248 nm and 193 nm" E. N. Sullivan, B. Nichols, S. von Kugelgen, G. da Silva, D. M. Neumark, J. Chem. Phys. 151, 174303 (2019). pdf

♦ "Fast beam photofragment translational spectroscopy of the phenoxy radical at 225 nm, 290 nm, and 533 nm" E. N. Sullivan, B. Nichols, D. M. Neumark, Phys. Chem. Chem. Phys. 21, 14720 (2019). pdf