Diverse photochemical behavior of dibromodifluoromethane (CF2Br2) monomer and cluster under gigawatt intensity laser fields

Abstract

Dibromodifluoromethane (CF₂Br₂) monomers and clusters were irradiated with nanosecond laser pulses of intensity ∼10⁹ W cm⁻² at 266 nm, 355 nm and 532 nm and the ionic outcome was studied using time-of-flight mass spectrometry. Based on the monomer study at different wavelengths, it was inferred that CF₂Br₂ undergoes dissociation followed by ionization and the primary dissociation leads to the formation of CF₂Br radical and atomic bromine. However, the cluster study reveals an altogether different photoionization channel. At 266 nm, CF₂Br⁺ and Br₂⁺ were observed in photoionization of CF₂Br₂ clusters and an intra-cluster photochemical reaction is responsible for the generation of these ions. Moreover, multiply charged ions of carbon, fluorine and bromine were observed at 355 nm and 532 nm. The mechanism of multiply charged ion formation due to the interaction of CF₂Br₂ clusters under a gigawatt intensity laser field has been discussed. Further, negative ions were detected in the photoionization of the CF₂Br₂ cluster at 532 nm and the effect of negative ions on the generation of multiply charged atomic ions will also be discussed.