Tin(IV) fluoride
Encyclopedia
Tin fluoride is a chemical compound
of tin
and fluorine
with the chemical formula
SnF4 and is a white solid with a melting point above 700 °C.
SnF4 can be prepared by the reaction of tin metal with fluorine gas:
However, a passivating metal fluoride layer will be created and the surface will eventually become unreactive. An alternative synthesis is the reaction of SnCl4
with anhydrous hydrogen fluoride
:
With alkali metal fluorides (e.g. KF) hexafluorostannates are produced (e.g.K2SnF6), which contain the octahedral SnF62− anion. SnF4 behaves as a Lewis acid
and adducts L2.SnF4 and L.SnF4 have been produced.
, tin(IV) bromide
, tin(IV) iodide
which contain tetrahedrally coordinated tin, tin(IV) fluoride has a planar structure consisting of octahedra sharing four corners with the terminal, unshared, fluorine atoms trans to one another. The melting point of SnF4 is much higher (700 °C) than the other tin(IV) halides which are relatively low melting, (SnCl4
, −33.3 °C; SnBr4
, 31 °C; SnI4
, 144 °C). The structure can also be contrasted with the tetrafluorides of the lighter members of group 14, (CF4, SiF4
and GeF4) which in the solid state form molecular crystals.
Commercial applications of the compound include using SnF4 in toothpaste
to prevent dental decay.
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...
of 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...
and fluorine
Fluorine
Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...
with the chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
SnF4 and is a white solid with a melting point above 700 °C.
SnF4 can be prepared by the reaction of tin metal with fluorine gas:
- Sn + 2F2 → SnF4
However, a passivating metal fluoride layer will be created and the surface will eventually become unreactive. An alternative synthesis is the reaction of SnCl4
Tin(IV) chloride
Tin chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4.At room temperature it is a colourless liquid, which fumes on contact with air, giving a stinging odor...
with anhydrous hydrogen fluoride
Hydrogen fluoride
Hydrogen fluoride is a chemical compound with the formula HF. This colorless gas is the principal industrial source of fluorine, often in the aqueous form as hydrofluoric acid, and thus is the precursor to many important compounds including pharmaceuticals and polymers . HF is widely used in the...
:
- SnCl4 + 4HF → SnF4 + 4HCl
With alkali metal fluorides (e.g. KF) hexafluorostannates are produced (e.g.K2SnF6), which contain the octahedral SnF62− anion. SnF4 behaves as a 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 adducts L2.SnF4 and L.SnF4 have been produced.
Structure
Unlike the other tin tetrahalides, tin(IV) chlorideTin(IV) chloride
Tin chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4.At room temperature it is a colourless liquid, which fumes on contact with air, giving a stinging odor...
, tin(IV) bromide
Tin(IV) bromide
Tin bromide is the chemical compound SnBr4. It is a colourless low melting solid.SnBr4 can be prepared by reaction of the elements at normal temperatures:In aqueous solution Sn64+ is the principal ionic species amongst a range of 6 coordinate ions with from 0-6 bromide ligands Tin(IV) bromide is...
, tin(IV) iodide
Tin(IV) iodide
Tin iodide, also known as stannic iodide is the chemical compound with the formula SnI4. This tetrahedral molecule crystallises as a bright orange solid that dissolves readily in nonpolar solvents such as benzene....
which contain tetrahedrally coordinated tin, tin(IV) fluoride has a planar structure consisting of octahedra sharing four corners with the terminal, unshared, fluorine atoms trans to one another. The melting point of SnF4 is much higher (700 °C) than the other tin(IV) halides which are relatively low melting, (SnCl4
Tin(IV) chloride
Tin chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4.At room temperature it is a colourless liquid, which fumes on contact with air, giving a stinging odor...
, −33.3 °C; SnBr4
Tin(IV) bromide
Tin bromide is the chemical compound SnBr4. It is a colourless low melting solid.SnBr4 can be prepared by reaction of the elements at normal temperatures:In aqueous solution Sn64+ is the principal ionic species amongst a range of 6 coordinate ions with from 0-6 bromide ligands Tin(IV) bromide is...
, 31 °C; SnI4
Tin(IV) iodide
Tin iodide, also known as stannic iodide is the chemical compound with the formula SnI4. This tetrahedral molecule crystallises as a bright orange solid that dissolves readily in nonpolar solvents such as benzene....
, 144 °C). The structure can also be contrasted with the tetrafluorides of the lighter members of group 14, (CF4, SiF4
Silicon tetrafluoride
Silicon tetrafluoride or Tetrafluorosilane is the chemical compound with the formula SiF4. This tetrahedral molecule is notable for having a remarkably narrow liquid range...
and GeF4) which in the solid state form molecular crystals.
Commercial applications of the compound include using SnF4 in toothpaste
Toothpaste
Toothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it serves as an abrasive that aids in removing the dental plaque and food from the teeth, assists in suppressing...
to prevent dental decay.