Is. Ignatyev et Hp. Schaefer, Bromine halides: The neutral molecules BrClFn (n=1-5) and their anions - Structures, energetics, and electron affinities, J AM CHEM S, 121(29), 1999, pp. 6904-6910
Density functional methods were used for predictions of the structures and
energetics of molecules and anions in the series BrClFn (n = 1-5). Very lit
tle is known from experiment about these potentially important interhalogen
molecules. Energy minima were found for all neutral molecules with the exc
eption of BrClF5. However, the dissociation limits for ClF elimination from
the BrClF3 (BHLYP and B3LYP only) and BrClF4 (all methods) molecules lie b
elow the energy of the respective ground states. All the BrClFn anions are
bound with respect to the corresponding neutrals; energy minima were found
for anions up to BrClF5-. Structures of isomers with the chlorine atom in t
he central position were also optimized. However, these local minima lie su
bstantially above the bromine-centered structures, and the energy gap betwe
en isomers grows with n. For the neutral molecules two paths of dissociatio
n were found to possess the lowest energies, i.e., chlorine atom and ClF el
imination. The latter channel becomes predominant at n > 1. For the anions
the lowest energy dissociation pathways are Cl- or Cl elimination, but for
n = 3, 5, ClF elimination becomes predominant. The adiabatic electron affin
ities, the vertical electron affinities of the BrClFn,, molecules, and the
vertical detachment energies of the BrClFn- anions were predicted in this w
ork. The adiabatic electron affinities of the closed-shell BrClFn molecules
significantly exceed those of the corresponding BrFn species, while for mo
lecules with an odd number of electrons they are similar or slightly lower
than electron affinities in the BrFn series. Many new experiments are sugge
sted by this researcher, in light of the large predicted electron affinitie
s and the fact that none of these has been measured in the laboratory.