Samarium(II) chloride (
Sm Cl2) is a
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
, used as a radical generating agent in the
ketone
In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo ...
-mediated intraannulation reaction.
Preparation
Reduction of
samarium(III) chloride
Samarium(III) chloride, also known as samarium trichloride, is an inorganic compound of samarium and chloride. It is a pale yellow salt that rapidly absorbs water to form a hexahydrate, SmCl3.6H2O. The compound has few practical applications but i ...
with samarium metal in a vacuum at a temperature of 800 °C to 900 °C, or with
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
gas at 350 °C yields samarium(II) chloride:
:2 SmCl
3 + Sm → 3 SmCl
2
:2 SmCl
3 + H
2 → 2 SmCl
2 + 2 HCl
Samarium(II) chloride can also be prepared by reducing samarium(III) chloride with
lithium metal/naphthalene in
THF
Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is ma ...
:
: SmCl
3 + Li → SmCl
2 + LiCl
A similar reaction has been observed with sodium.
Structure
Samarium(II) chloride adopts the
PbCl2 (
cotunnite
Cotunnite is the natural mineral form of lead(II) chloride with formula PbCl2.
It was first described in 1825 from an occurrence on Mount Vesuvius, Naples Province, Campania, Italy. It was named for Domenico Cotugno (Cotunnius) (1736–1822), Ita ...
) structure.
References
Chlorides
Lanthanide halides
Samarium compounds
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