# Matrix Isolation of the Arsinoborene F2B–As=BF with an As=B Double Bond Character

## TL;DR

Scientists created a new compound with a double bond between arsenic and boron, expanding our understanding of chemical bonding between these elements.

## Contribution

The first experimental confirmation of an arsinoborene with a genuine As=B double bond and two-coordinate atoms.

## Key findings

- F2B–As=BF was synthesized with a genuine As=B double bond and two-coordinate As and B atoms.
- FB–AsF2 and F2B–AsF were identified through infrared spectroscopy and isotope substitution.
- UV irradiation triggers isomerization from FB–AsF2 to F2B–AsF in argon matrices.

## Abstract

We report on the generation of F2B–As=BF,
an arsinoborene (boranylidenearsane) with a genuine As=B double
bond, where both the As and B atoms are two-coordinate. It was obtained
from the reaction of AsF3 with laser-ablated boron atoms
under cryogenic conditions in neon and argon matrices. In addition,
the single-bonded arsenic–boron radicals FB–AsF2 and F2B–AsF were characterized. These species
were identified by infrared spectroscopy and 10/11B isotope
substitution in conjunction with quantum-chemical calculations at
the B3LYP and CCSD(T) levels of theory. The isomerization from FB–AsF2 to F2B–AsF can be triggered by irradiation
with ultraviolet light (λ = 275 nm) in argon. This discovery
of the arsinoborene F2B–As=BF further extends
the series of multiple-bonded systems between heavy main group elements
and boron.

The arsinoborene F2B−As=BF features
two-coordinate arsenic and boron atoms and a genuine As=B double
bond. Additionally, the photolysis behavior of new boron−arsenic
compounds upon irradiation with ultraviolet (UV) light of λ
= 275 nm enabled the spectroscopic identification of FB−AsF2 and F2B−AsF.