Answers are grounded in this paper and cite their sources.
Despite a formal negative charge on boron, no LiċB coordination is found in borataallene 1. Instead, the Li ions are coordinated by the aryl C atoms and an allene C atom. In diboratabutadiene 2, one Li ion is also coordinated by aryl C atoms. The other is coordinated by the butadiene unit and two Si methyl groups. Aryl = 2,4,6-Me3C6H2.
No takes yet. Share an insight, caveat, or question.
Pilz et al. (1990) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: