Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Mar 15;60(12):6682-6690.
doi: 10.1002/anie.202014398. Epub 2021 Feb 9.

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

Jacob E Walley  1 , Levi S Warring  1 , Guocang Wang  1 , Diane A Dickie  1 , Sudip Pan  2 , Gernot Frenking  2 , Robert J Gilliard Jr  1
Affiliations

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

Jacob E Walley et al. Angew Chem Int Ed Engl. .

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.

Keywords: bismaalkenes; carbenes; carbodicarbenes; cations; low-coordinate compounds.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Representative examples of bismuth cations (A–C). Previous work: carbene‐bismuthinidene (D). This work: carbodicarbene‐bismaalkene cations.
Figure 2
Figure 2
Structurally characterized examples of neutral and cationic pnictaalkenes.
Scheme 1
Scheme 1
Synthesis of bismuth cations supported by N‐heterocyclic carbenes and a cyclic(alkyl)(amino) carbene.
Scheme 2
Scheme 2
Synthesis of NHC‐ and CDC‐ supported phenylbismuth dichloride (NHC=4,5‐dimethyl‐1,3‐diisopropylimidazolin‐2‐ylidene; CDC=bis(1‐isopropyl‐3‐methyl‐benzimidazol‐2‐ylidene)methane.
Figure 3
Figure 3
Molecular structures of 6 and 7 (thermal ellipsoids at 50 % probability; H atoms omitted for clarity). 6: C1‐Bi1: 2.346(2); Bi1—Cl2′: 3.2473(7); Bi1‐Cl1: 2.6857(6); Bi1‐Cl2: 2.7031(6). Cl1‐Bi1‐Cl2: 166.081(18); Cl2‐Bi1‐C1: 99.21(8); Cl1‐Bi1‐C1: 84.96(5); C12‐Bi1‐Cl1: 92.21(6); C12‐Bi1‐Cl2: 91.65(6); C12‐Bi1‐C1: 99.21(8). 7: C1‐Bi1: 2.249(6); Bi1‐Cl1: 2.7693(14); Bi1‐Cl2: 2.6989(15); Bi1‐C24: 2.275(12); C1‐C2: 1.393(8); C1‐C13:1.445(8). Cl1‐Bi1‐Cl2: 176.21(5); Cl2‐Bi1‐C1: 90.52(15); Cl1‐Bi1‐C1: 93.23(15); C24‐Bi1‐Cl1: 89.8(5); C24‐Bi1‐Cl2: 89.2(5); C24‐Bi1‐C1: 97.2(6).
Scheme 3
Scheme 3
Synthesis of CDC‐stabilized bismuth mono‐ and di‐cations with increasing bismaalkene character.
Figure 4
Figure 4
Molecular structures of 8 and 9 (thermal ellipsoids at 50 % probability; H atoms were omitted for clarity). 8: C1‐Bi1: 2.226(3); Bi1‐Cl1: 2.5573(9); C24‐Bi1: 2.242(3); C1‐C2: 1.417(5); C1‐C13: 1.427(5); Bi1—F1: 2.904(2). C1‐Bi1‐Cl1: 102.82(9); C1‐Bi1‐C24: 93.60(13); C24‐Bi1‐Cl1: 93.86(10). 9: C1‐Bi1: 2.157(11); Bi1‐C24: 2.223(12); C1‐C2: 1.444(15); C1‐C13: 1.426(15); Bi1—F1: 2.603(8); Bi1—F7: 2.740(7); C1‐Bi1‐C24: 96.7(4).
Scheme 4
Scheme 4
Synthesis of a bis‐CDC‐supported tribromobismuth dimer.
Figure 5
Figure 5
Molecular structures of 10–13 (thermal ellipsoids at 50 % probability; H atoms, counteranions and non‐coordinating solvent omitted for clarity). 10: Bi1‐C1: 2.292(9); Bi1‐Br1: 2.9196(12); Bi1‐Br2: 2.6483(11); Bi1‐Br3: 2.8390(12); Bi1—Br1′: 3.4829(15); C1‐C13: 1.367(13); C1‐C2: 1.438(12). 11: Bi1‐C1: 2.226(12); Bi1‐Br2: 2.6629(16); Bi1‐Br1: 2.7052(18); C1‐C13: 1.395(17); C1‐C2: 1.447(15). 12: Bi1‐Br1: 2.6439(6); Bi1‐C1: 2.199(5); C1‐C2: 1.441(6); C1‐C13: 1.433(6). 13: Bi1‐C24: 2.166(2); Bi1‐C1: 2.197(2); C1‐C13: 1.424(3); C1‐C2: 1.443(3); C24‐C25: 1.436(3); C24‐C36: 1.444(3). C24‐Bi1‐C1: 111.23(9).
Scheme 5
Scheme 5
Synthesis of CDC mono‐, di‐, and tri‐positive bismuthenium ions. Note: similar to compound 9, compounds 12 and 13 can be represented as resonance structures with their respective zwitterions as shown in Scheme 3.
See this image and copyright information in PMC

References

    1. None
    1. Kindervater M. B., Marczenko K. M., Werner-Zwanziger U., Chitnis S. S., Angew. Chem. Int. Ed. 2019, 58, 7850–7855; - PubMed
    2. Angew. Chem. 2019, 131, 7932–7937;
    1. Turner Z. R., Inorg. Chem. 2019, 58, 14212–14227; - PubMed
    1. Marczenko K. M., Chitnis S. S., Chem. Commun. 2020, 56, 8015–8018; - PubMed
    1. Mukhopadhyay D. P., Schleier D., Wirsing S., Ramler J., Kaiser D., Reusch E., Hemberger P., Preitschopf T., Krummenacher I., Engels B., Fischer I., Lichtenberg C., Chem. Sci. 2020, 11, 7562–7568; - PMC - PubMed

Grants and funding

LinkOut - more resources