# A Crystalline In(II) Hydride

## TL;DR

Scientists created a stable crystalline hydride of indium, which could help in activating small molecules and catalysis.

## Contribution

The first stable, crystalline In(II) hydride supported by bis(N-heterocyclic carbene)borate ligands is synthesized and characterized.

## Key findings

- The compound features a covalent In–In bond and is stabilized by bis(N-heterocyclic carbene)borate ligands.
- It shows nucleophilic behavior in preliminary reactivity tests, suggesting potential for bond activation.
- Stability is confirmed through NMR, X-ray diffraction, and computational studies.

## Abstract

Low oxidation state hydride species of heavier main-group
elements
are notoriously elusive due to their intrinsic instability and rapid
decomposition, generating hydrogen. Nevertheless, they offer significant
potential for small-molecule activation and catalysis. Herein, we
report the synthesis and characterization of the first stable, crystalline,
low oxidation state indium hydride, supported by bis­(N-heterocyclic carbene)­borate ligands and featuring a covalent In–In
bond. This compound has been comprehensively characterized by NMR
spectroscopy, FT-IR, single-crystal X-ray diffraction, and computational
calculations. Experimental and theoretical studies reveal key features
that underpin its exceptional stability. Preliminary reactivity investigations
demonstrate that this discrete In­(II) hydride acts as a nucleophile,
opening new avenues for bond activation involving hydrides derived
from the heaviest p-block elements.