Samarium(II) chloride (SmCl2) is a chemical compound, used as a radical generating agent in the ketone-mediated intraannulation reaction. Preparation Reduction of samarium(III) chloride with samarium metal in a vacuum at a temperature of 800 °C to 900 °C, or with hydrogen gas at 350 °C yields samarium(II) chloride: 2 SmCl3 + Sm → 3 SmCl2 2 SmCl3 + H2 → 2 SmCl2 + 2 HCl Samarium(II) chloride can also be prepared by reducing samarium(III) chloride with lithium metal/naphthalene in THF: SmCl3 + Li → SmCl2 + LiCl A similar reaction has been observed with sodium. Structure Samarium(II) chloride adopts the PbCl2 (cotunnite) structure. References Chlorides Lanthanide halides Samarium compounds