# Zinc Metallacarborane Chemistry

## TL;DR

This paper introduces new zinc-based carborane complexes and reveals insights into their bonding and structure.

## Contribution

The synthesis of novel zincacarborane complexes and the characterization of their bonding through experimental and computational methods.

## Key findings

- New zincacarborane complexes with unique structures were synthesized using N-heterocyclic carbenes and other ligands.
- Computational studies revealed ionic Zn–dicarbollide bonding with some covalent character and weak Zn···Zn interactions.
- The bonding is exclusively to boron atoms, challenging previous assumptions about d10 metal–carborane interactions.

## Abstract

This work presents
a new family of zincacarborane complexes
synthesized
from ZnMe2 and [C2B9H13], using neutral two-electron donor ligands: N-heterocyclic
carbenes (NHCs) yield the first closo-12-vertex half-sandwich
zincocenes, [(NHC)­Zn­(C2B9H11)] (1–3), while bulkier NHCs form slipped
bis-dicarbollide salts (4–5). Use
of pyridine leads to the macropolyhedral dimer (6) with
a planar {Zn2B2} motif, and triphenylphosphine
gives a V-shaped η3-borallyl complex (7). Structures have been confirmed by single-crystal X-ray diffraction
and NMR spectroscopy. Computational studies (DFT and QTAIM) show predominantly
ionic Zn–dicarbollide bonding with notable polar covalent character.
Apparent Zn···Zn interactions are weak electrostatic
contacts, and metal–ligand bonding is exclusively to boron
atoms. Together, these findings broaden the structural and electronic
landscape of zincacarboranes, challenge assumptions about d10 metal–carborane bonding, and offer a new platform for exploring
group 12 metallacarborane reactivity.