Long-lived molecular anions of brominated diphenyl ethers.

This article focuses on the investigation of resonance dissociative electron attachment (DEA) in brominated diphenyl ethers—specifically 4-bromodiphenyl ether (BDPE), 4-bromophenyl ether (BPE), and decabromodiphenyl ether (DBDE)—using gas-phase mass spectrometry and density functional theory (DFT) calculations. The study detected long-lived molecular negative ions with autodetachment lifetimes of approximately 57 µs for BPE and 63 µs for DBDE, while BDPE did not form such long-lived anions due to its lower electron affinity. Fragmentation patterns primarily involved bromine anions and related species, with DBDE showing a notable decomposition of the [C6Br5O]− anion into bromide and a neutral cyclopentadienylidene derivative. The findings contribute to understanding the electron attachment behavior of these compounds, which are relevant as flame retardants with environmental and health implications.