Tin(IV) chloride
Encyclopedia
Tin chloride, also known as tin tetrachloride or stannic chloride is a chemical compound
with the formula Sn
Cl
4.
At room temperature it is a colourless liquid
, which fumes on contact with air, giving a stinging odor. It was first discovered by Andreas Libavius
(1550–1616) and was known as "spiritus fumans libavii" .
gas with elemental tin
.
With hydrochloric acid the complex [SnCl6]2− is formed making the so-called hexachlorostannic acid.
Anhydrous tin(IV) chloride is a strong Lewis acid
and complexes with e.g. ammonia
, phosphine
and phosphorus pentachloride are known. SnCl4 is used in Friedel-Crafts reaction
s as a catalyst for homogeneous alkylation and cyclisation.
With Grignard reagents tetraalkyltin compounds can be prepared:
, as it formed an irritating (but non-deadly) dense smoke on contact with air: it was substituted for by a mixture of silicon tetrachloride
and titanium tetrachloride
near the end of the War due to shortages of tin. It is also used in the glass container industry for making an external coating containing tin(IV) oxide which toughens the glass. It is a starting material for organotin
compounds.
Stannic chloride is used in chemical reactions with fuming (90%) nitric acid for the selective nitration of activated aromatic rings in the presence of unactivated ones.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula Sn
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
Cl
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
4.
At room temperature it is a colourless liquid
Liquid
Liquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
, which fumes on contact with air, giving a stinging odor. It was first discovered by Andreas Libavius
Andreas Libavius
Andreas Libavius was a German doctor and chemist.-Life:Libavius was born in Halle, Germany, as Andreas Libau. In Halle he attended the gymnasium and studied from the year 1576 in University of Wittenberg. From 1577 on he studied in the University of Jena in the faculties of philosophy and history...
(1550–1616) and was known as "spiritus fumans libavii" .
Preparation
It is prepared from reaction of chlorineChlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
gas with elemental tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
.
- Sn + 2 Cl2 → SnCl4
Reactions
When mixed with a small amount of water a semi-solid crystalline mass of the pentahydrate, SnCl4.5H2O is formed. This was formerly known as butter of tin. This compound has been shown to be best described as [SnCl4(H2O)2].3H2O, consisting of cis-[SnCl4(H2O)2] units linked in chains with three hydrate water molecules.With hydrochloric acid the complex [SnCl6]2− is formed making the so-called hexachlorostannic acid.
Anhydrous tin(IV) chloride is a strong Lewis acid
Lewis acid
]The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in 1923, specifically: An acid substance is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms. Thus, H+ is a Lewis acid, since it can accept a lone pair,...
and complexes with e.g. ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
, phosphine
Phosphine
Phosphine is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas. Pure phosphine is odourless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphine...
and phosphorus pentachloride are known. SnCl4 is used in Friedel-Crafts reaction
Friedel-Crafts reaction
The Friedel–Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877. There are two main types of Friedel–Crafts reactions: alkylation reactions and acylation reactions. This reaction type is a form of electrophilic aromatic substitution...
s as a catalyst for homogeneous alkylation and cyclisation.
With Grignard reagents tetraalkyltin compounds can be prepared:
- SnCl4 + RMgCl → SnR4
Uses
Stannic chloride was used as a chemical weapon in World War IWorld War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, as it formed an irritating (but non-deadly) dense smoke on contact with air: it was substituted for by a mixture of silicon tetrachloride
Silicon tetrachloride
Silicon tetrachloride is the inorganic compound with the formula SiCl4. It is a colourless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications.-Preparation:...
and titanium tetrachloride
Titanium tetrachloride
Titanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
near the end of the War due to shortages of tin. It is also used in the glass container industry for making an external coating containing tin(IV) oxide which toughens the glass. It is a starting material for organotin
Organotin
Organotin compounds or stannanes are chemical compounds based on tin with hydrocarbon substituents. Organotin chemistry is part of the wider field of organometallic chemistry. The first organotin compound was diethyltin diiodide, discovered by Edward Frankland in 1849...
compounds.
Stannic chloride is used in chemical reactions with fuming (90%) nitric acid for the selective nitration of activated aromatic rings in the presence of unactivated ones.