Syntheses, Geometric and Electronic Structures of Inorganic Cumulenes

Journal article

Molecular chains of two-coordinate carbon atoms (cumulenes) have long been targeted, due to interest in the electronic structure and applications of extended π-systems, and their relationship to the carbon allotrope, carbyne. While formal (isoelectronic) BN for CC substitution has been employed in two-dimensional (2-D) materials, unsaturated one-dimensional all-inorganic “molecular wires” are unknown. Here, we report high-yielding synthetic approaches to heterocumulenes containing a five-atom BNBNB chain, the geometric structure of which can be modified by choice of end group. The diamido-capped system is bent at the 2-/4-positions, and natural resonance theory calculations reveal significant contributions from BN(:)–BN–B resonance forms featuring a lone pair at N (consistent with observed N-centered nucleophilicity). Molecular modification to generate a linear system best described by a BNBNB resonance structure involves chemical transformation of the capping groups (using B­(C5F5)3) to enhance their π-acidity and conjugate the N-lone pairs.

Authors: Tang, J; Hu, C; Crumpton, AE; Dietz, M; Sarkar, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Journal of the American Chemical Society
• Volume: 146
• Issue: 45
• Pages: 30778-30783
• Publication date: 2024-11-04
• Acceptance date: 2024-10-21
• DOI: 10.1021/jacs.4c13231
• EISSN: 1520-5126
• ISSN: 0002-7863
• Language: English