Inverse Bonding - Backbonding: Metal to Ligand σ and Ligand to Metal π Dative Interactions between Bismuth and Boron

There are many types of coordinating bond types, but an inverse bonding-backbonding (IBBB) with a metal to ligand sigma donation and a ligand to metal pi backdonation (a sigma Z-pi L interaction) is unheard of. Herein we computationally describe one such case based on a borabenzene ligand and a bismuth pincer complex. We believe that IBBB involving d orbitals in transition metals is impossible, but a pi charge transfer to a post-transition metal empty p orbital can do the trick.

Automated summary

This article describes a previously unheard of type of coordinating bond, and computationally investigates one such case involving a borabenzene ligand and a bismuth pincer complex. The study suggests that inverse bonding-backbonding (IBBB) involving d orbitals in transition metals is impossible, but a pi charge transfer to a post-transition metal empty p orbital can achieve it.