Carbodicarbene Bismaalkene Cations: Unravelling the Complexities of Carbene versus Carbone in Heavy Pnictogen Chemistry.

ABSTRACT: We report a combined experimental and theoretical study on the first examples of carbodicarbene (CDC)-stabilized bismuth complexes, which feature low-coordinate cationic bismuth centers with C=Bi multiple-bond character. Monocations [(CDC)Bi(Ph)Cl][SbF₆ ] (8) and [(CDC)BiBr₂ (THF)₂ ][SbF₆ ] (11), dications [(CDC)Bi(Ph)][SbF₆ ]₂ (9) and [(CDC)BiBr(THF)₃ ][NTf₂ ]₂ (12), and trication [(CDC)₂ Bi][NTf₂ ]₃ (13) have been synthesized via sequential halide abstractions from (CDC)Bi(Ph)Cl₂ (7) and (CDC)BiBr₃ (10). Notably, the dications and trication exhibit C ⇉ Bi double dative bonds and thus represent unprecedented bismaalkene cations. The synthesis of these species highlights a unique non-reductive route to C-Bi π-bonding character. The CDC-[Bi] complexes (7-13) were compared with related NHC-[Bi] complexes (1, 3-6) and show substantially different structural properties. Indeed, the CDC ligand has a remarkable influence on the overall stability of the resulting low-coordinate Bi complexes, suggesting that CDC is a superior ligand to NHC in heavy pnictogen chemistry.

SUBMITTER: Walley JE 

PROVIDER: S-EPMC7986408 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature