Hexafluorophosphoric acid
Encyclopedia
Hexafluorophosphoric acid is the chemical compound
with the chemical formula
HPF6. This strong Brønsted acid features a non-coordinating anion
, hexafluorophosphate
. It is formed from the reaction of hydrogen fluoride
with phosphorus pentafluoride
.
Like many strong acids, hexafluorophosphoric acid is not isolable but is handled only in solution. Its aqueous solutions consist of hydronium ion, , and . Additionally such solutions contain products derived from hydrolysis of the P-F bonds, including , , and , and their conjugate bases.
"Crystalline " has been obtained as the hexahydrate, wherein is enclosed in truncated octahedral
cages defined by the water and protons. NMR spectroscopy
indicates that solutions derived this hexahydrate contain significant amounts of HF.
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 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....
HPF6. This strong Brønsted acid features a non-coordinating anion
Non-coordinating anion
Anions that interact weakly with cations are termed non-coordinating anions, although a more accurate term is 'weakly coordinating anion'. Non-coordinating anions are useful in studying the reactivity of electrophilic cations. They are commonly found as counterions for cationic metal complexes...
, hexafluorophosphate
Hexafluorophosphate
Hexafluorophosphate is an anion with chemical formula of . This octahedral species is isoelectronic with sulfur hexafluoride, SF6, and is valence isoelectronic with the highly stable superacid anion fluoroantimonate . As a non-coordinating anion, it is a poor nucleophile...
. It is formed from the reaction of 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...
with phosphorus pentafluoride
Phosphorus pentafluoride
Phosphorus pentafluoride, PF5, is a phosphorus halide. It's a colourless gas at room temperature and pressure.-Structure:Single-crystal X-ray studies indicate PF5 molecule has two distinct P−F bonds : P−Fax = 158.0 pm and P−Feq = 152.2 pm...
.
Like many strong acids, hexafluorophosphoric acid is not isolable but is handled only in solution. Its aqueous solutions consist of hydronium ion, , and . Additionally such solutions contain products derived from hydrolysis of the P-F bonds, including , , and , and their conjugate bases.
"Crystalline " has been obtained as the hexahydrate, wherein is enclosed in truncated octahedral
Truncated octahedron
In geometry, the truncated octahedron is an Archimedean solid. It has 14 faces , 36 edges, and 24 vertices. Since each of its faces has point symmetry the truncated octahedron is a zonohedron....
cages defined by the water and protons. NMR spectroscopy
NMR spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained...
indicates that solutions derived this hexahydrate contain significant amounts of HF.