Cobalt(II) hydride

Cobalt(II) hydride is an inorganic compound with a chemical formula CoH₂. It has dark grey crystals. It oxidizes slowly in air and reacts with water.^[1][2]

Cobalt(II) hydride

Names
Other names Cobalt dihydride, cobaltous hydride
Identifiers
3D model (JSmol)	Interactive image
ChemSpider	464927
PubChem CID	22450701
InChI InChI=1S/Co.2H/q+2;2*-1 Key: RDKRCUAPGSVALD-UHFFFAOYSA-N
SMILES [H-].[H-].[Co+2]
Properties
Chemical formula	CoH2
Molar mass	60.949 g·mol−1
Appearance	dark grey crystals
Density	0.533 g/cm3
Solubility in water	reacts
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	highly reacts
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Two forms of cobalt(II) hydride exist under high pressure. From 4 to 45 GPa there is a face-centred cubic form with formula CoH. This can be decompressed at low temperatures to form a metastable compound at atmospheric pressure. Over 45 GPa a cobalt(II) hydride CoH₂ also crystallises in a face-centred cubic form.^[3]

Preparation

Cobalt(II) hydride can prepared by reacting phenylmagnesium bromide and cobalt(II) chloride in hydrogen gas:

CoCl₂ + 2 C₆H₅MgBr + 2 H₂ → CoH₂ + 2 C₆H₆ + MgBr₂ + MgCl₂