Pulsed Jet Discharge Matrix Isolation and Computational Study of Bromine Atom Complexes: Br···BrXCH₂ (X = H, Cl, Br)

Abstract

Halogen atoms are important reactive radicals in the atmosphere. In this work, pulsed jet discharge matrix isolation spectroscopy and computational methods were used to characterize prereactive complexes of halogen atoms with simple halons. Our experiments combined matrix isolation techniques with a pulsed DC discharge nozzle, where a dilute CH(2)XBr (X = H, Cl, Br)/rare gas sample was gently discharged and the products were deposited onto a cold KBr window. The Br···BrCH(2)X (X = H, Cl, Br) complexes were characterized by infrared and electronic spectroscopy, supported by ab initio and density functional theory (DFT) calculations, which shed light on the structure of, bonding in, and binding energy of the complexes. The correlation of charge-transfer energy with donor ionization potential (Mulliken correlation) was examined, and the charge-transfer photochemistry of the complexes was explored.

Solvent-Dependent Photochemistry of 2,2,2-Tribromoethyl-(2′-phenylacetate)

“…Reid et al have argued, on the basis of computational studies, that an ion-pair (RCBr 2 + ···Br − ) resonance structure is a significant contributor for 9 in the condensed phase and that Hbonding solvents such as water should help stabilize this species. 27 This is certainly consistent with our observations of significant products formed via 9 when water and other Hbonding species (see below) are added. Adding water to the Scheme 1.…”

The Effect of Explicit Solvent on Photodegradation of Decabromodiphenyl Ether in Toluene: Insights from Theoretical Study

“…The effects of an explicit toluene solvent molecule on photodegradation reaction of BDE209 are investigated by using the density functional theory (DFT) , and time-dependent − density functional theory (TD-DFT). The M06 functional combined with the TD method is employed, which has been proven successful in describing the noncovalent interactions and the excitation properties of certain organic compounds. − The hybrid basis set denoted as 6-311+G(d)-LANLdp is used for all calculations. For bromine, the LANL2DZ basis set is used and is augmented with polarization functions of d symmetry and diffuse functions of p symmetry .…”

Double Hydrogen-Atom Exchange Reactions of HX (X = F, Cl, Br, I) with HO2

“…These issues can be resolved by using DFT with effective core potentials. Previous studies have shown that reliable geometries, energies, and frequencies can be obtained when effective core potentials are used in tandem with density functional theory (DFT). − Effective core potentials were only available for the heavier halides iodine and bromine, whereas for chlorine and fluorine no effective core potential was available (or needed) and thus the full electron representation was used in the computations. We employed the Minnesota functional M11 .…”