Molybdenum(III) chloride is the
inorganic compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...
with the formula MoCl
3. It forms purple crystals.
Synthesis and structure
Molybdenum(III) chloride is synthesized by the
reduction of
molybdenum(V) chloride
Molybdenum(V) chloride is the inorganic compound with the empirical formula . This dark volatile solid is used in research to prepare other molybdenum compounds. It is moisture-sensitive and soluble in chlorinated solvents.
Structure
Usually cal ...
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 ...
. 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 aci ...
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 commonly reducing agents include the Earth meta ...
.
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 hexahydrate with the formula , containing six water molecules of hydration. Both are colourless crystals, but samples are often contam ...
(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 occu ...
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 in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable liq ...
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)
Hexa(''tert''-butoxy)dimolybdenum(III) is a coordination complex of molybdenum(III). It is one of the homoleptic alkoxides of molybdenum. An orange, air-sensitive solid, the complex has attracted academic attention as the precursor to many organ ...
is prepared by the
salt metathesis
A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding a ...
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
Molybdenum halides
Molybdenum(III) compounds
{{Inorganic-compound-stub