Scandium chloride is the inorganic compound

Inorganic compound

Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...

 with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 ScCl₃. It is a white, high-melting ionic compound

Ionic compound

In chemistry, an ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion. Ions in ionic compounds are held together...

, which is deliquescent and highly water soluble. Scandium(III) chloride is mainly of interest in the research laboratory. Both the anhydrous

Anhydrous

As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...

 form and hexahydrate

Hydrate

Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....

 (ScCl₃•6H₂O) are commercially available.

Chemical and physical properties

ScCl₃ crystallises in the layered BiI₃ motif, which features octahedral scandium centres. Monomeric ScCl₃ is the predominant species in the vapour phase at 900 K, the dimer Sc₂Cl₆ accounts for approximately 8%. The electron diffraction spectrum indicates that the monomer is planar and the dimer is bridged with four Sc-Cl bonds.

Reactions

ScCl₃ dissolves in water to give [Sc(H₂O)]³⁺ ions. In fact, samples of ScCl₃ converts to this hexahydrate upon exposure to air. With the less basic ligand

Ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...

 tetrahydrofuran

Tetrahydrofuran

Tetrahydrofuran is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. This heterocyclic compound has the chemical formula 4O. As one of the most polar ethers with a wide liquid range, it is a useful solvent. Its main use, however, is as a precursor...

, ScCl₃ yields the adduct

Adduct

An adduct is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species...

 ScCl₃(THF)₃ as white crystals. This THF-soluble complex is used in the synthesis of organoscandium compounds. ScCl₃ has been converted to its dodecyl sulfate salt

Sodium dodecyl sulfate

Sodium dodecyl sulfate , sodium laurilsulfate or sodium lauryl sulfate is an organic compound with the formula CH311OSO3Na). It is an anionic surfactant used in many cleaning and hygiene products...

, which has been investigated as a "Lewis acid-surfactant combined catalyst" (LASC) in aldol-like reactions

Aldol reaction

The aldol reaction is a powerful means of forming carbon–carbon bonds in organic chemistry.Discovered independently by Charles-Adolphe Wurtz and Alexander Porfyrevich Borodin in 1872, the reaction combines two carbonyl compounds to form a new β-hydroxy carbonyl compound...

.

Reduction

Scandium(III) chloride was used by Fischer et al. who first prepared metallic scandium by electrolysis

Electrolysis

In chemistry and manufacturing, electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction...

 of a eutectic melt of scandium(III) chloride and other salts at 700-800 °C.

ScCl₃ reacts with scandium metal to give a number of chlorides where scandium has an oxidation state <+3, ScCl, Sc₇Cl₁₀, Sc₂Cl₃, Sc₅Cl₈ and Sc₇Cl₁₂. For exampled, reduction of ScCl₃ with scandium metal in the presence of caesium chloride

Caesium chloride

Caesium chloride is the inorganic compound with the formula CsCl. This colorless solid is an important source of caesium ions in a variety of applications. Its crystal structure forms a major structural type where each caesium ion is coordinated by 8 chlorine ions...

 gives the compound CsScCl₃ which contain linear chains of composition ScCl₃⁻.

Uses

Scandium(III) chloride is found in some halide lamps

Metal halide lamp

Metal-halide lamps, a member of the high-intensity discharge family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source. By adding rare earth metal salts to the mercury vapor lamp, improved luminous efficacy and light color is obtained...

, optical fiber

Optical fiber

An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...

s, electronic ceramics, and lasers.