Molybdenum(III) chloride is the
inorganic compound
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''.
Inorgan ...
with the formula MoCl
3. It forms purple crystals.
Synthesis and structure
Molybdenum(III) chloride is synthesized by the
reduction of
molybdenum(V) chloride with
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
. A higher yield is produced by the reduction of pure molybdenum(V) chloride with anhydrous
tin(II) chloride
Tin(II) chloride, also known as stannous chloride, is a white crystalline solid with the formula . It forms a stable dihydrate, but aqueous solutions tend to undergo hydrolysis, particularly if hot. SnCl2 is widely used as a reducing agent (in ac ...
as the
reducing agent
In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an (called the , , , or ).
Examples of substances that are common reducing agents include hydrogen, carbon ...
.
Molybdenum trichloride exists as two
polymorphs: alpha (α) and beta (β). The alpha structure is similar to that of
aluminum chloride
Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms a hexahydrate with the formula , containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are col ...
(AlCl
3). In this structure, molybdenum has octahedral coordination geometry and exhibits cubic
close-packing
In geometry, close-packing of equal spheres is a dense arrangement of congruent spheres in an infinite, regular arrangement (or lattice). Carl Friedrich Gauss proved that the highest average density – that is, the greatest fraction of space occ ...
in its crystalline structure. The beta structure, however, exhibits hexagonal close packing.
Ether complexes
Molybdenum trichloride gives a
ether complexes MoCl
3(thf)
3 and MoCl
3(Et
2O)
3. They are beige, paramagnetic solids. Both feature octahedral Mo centers. The
diethyl ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...
complex is synthesized by reducing a Et
2O solution of MoCl
5 with tin powder. Older procedures involve stepwise reduction involving isolation of the Mo(IV)-thf complex.
Hexa(tert-butoxy)dimolybdenum(III) is prepared by the
salt metathesis
A salt metathesis reaction (also called a double displacement reaction, double replacement reaction, or double decomposition) is a type of chemical reaction in which two ionic compounds in aqueous solution exchange their component ions to form two ...
reaction from MoCl
3(thf)
3:
:2 MoCl
3(thf)
3 + 6 LiOBu-t → Mo
2(OBu-t)
6 + 6 LiCl + 6 thf
References
{{Chlorides
Chlorides
Molybdenum halides
Molybdenum(III) compounds