Relevance of π-Backbonding for the Reactivity of Electrophilic Anions [B₁₂ X₁₁ ]^- (X=F, Cl, Br, I, CN).

ABSTRACT: Electrophilic anions of type [B₁₂ X₁₁ ]^- posses a vacant positive boron binding site within the anion. In a comparatitve experimental and theoretical study, the reactivity of [B₁₂ X₁₁ ]^- with X=F, Cl, Br, I, CN is characterized towards different nucleophiles: (i) noble gases (NGs) as σ-donors and (ii) CO/N₂ as σ-donor-π-acceptors. Temperature-dependent formation of [B₁₂ X₁₁ NG]^- indicates the enthalpy order (X=CN)>(X=Cl)≈(X=Br)>(X=I)≈(X=F) almost independent of the NG in good agreement with calculated trends. The observed order is explained by an interplay of the electron deficiency of the vacant boron site in [B₁₂ X₁₁ ]^- and steric effects. The bin

SUBMITTER: Mayer M 

PROVIDER: S-EPMC8362024 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature