Hydrido Complexes of Calcium: A New Family of Molecular Alkaline‐Earth‐Metal Compounds

The application of solid calcium hydride CaH2 has been mostly confined to its use as a desiccant, although its catalytic activity has long been known. Since the first isolation of a well‐defined molecular calcium hydride in 2006, the past decade has witnessed a gradual emergence of this new family of compounds. Although the detrimental Schlenk equilibrium has kept the number of examples low, the novelty of their reactivity, especially in small‐molecule activation, holds great promise. This Minireview gives an overview of the molecular calcium hydrides reported to date, highlighting their synthesis, structure, and reactivity. More than just a drying agent: Structurally well‐defined molecular calcium hydrides are summarized in this Minireview, with a focus on their synthesis, structure, and reactivity, including catalysis.