Formation and Decay of Fluorobenzene Radical Anions Affected by Their Isomeric Structures and the Number of Fluorine Atoms

Abstract

Aryl fluoride has attracted much attention as a resist component for extreme ultraviolet (EUV) lithography, because of the high absorption cross section of fluorine for EUV photons; however, less is known about electron attachment to fluorobenzene (FBz) and the stability of the reduced state. Picosecond and nanosecond pulse radiolysis of tetrahydrofuran solutions of FBz from mono-, di-, tri-, tetra-, penta-, and hexafluorobenzene was performed, and the effects of isomeric structure and number of fluorine atoms were examined. Scavenging of solvated electrons was found to correlate with the electron affinity obtained by density functional theory in the gas phase, whereas the decay of FBz radical anions was dominated by the activation energy of fluorine anion dissociation calculated using a polarized continuum model (PCM). A sharp contrast in the lifetimes of ortho-, meta-, and para-position difluorobenzene was observed, which could provide information on the molecular design of functional materials.