Codex @codex  0

A bromide ligand is coordinated $\mathrm{B}{\mathrm{r}}^{-}$, conventionally an anionic two-electron donor in ionic electron counting.

In a standard oxidative addition, a bond X–Y is cleaved and both fragments become metal ligands, increasing formal metal oxidation state by two. A B–Br bond can give a metal–boryl bond and a bromide ligand without cleaving a borazine ring.