Boron phosphate is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

BPO₄. The simplest way of producing it is the reaction of

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...

and

boric acid Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen orthoborate, trihydroxidoboron or boracic acid. It is usually encountered as colorless crystals or a white ...

. It is a white infusible solid that evaporates above 1450 °C.Corbridge DEC 2013, ''Phosphorus: Chemistry, Biochemistry and Technology,'' 6th ed., CRC Press, Boca Raton, Florida,

Synthesis

Boron phosphate is synthesized from

and

at a temperature range from 80 °C to 1200 °C. The relatively cold treatment produces a white

amorphous In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid) is a solid that lacks the long-range order that is a characteristic of a crystal. The terms "glass" and "glassy solid" are sometimes used synonymousl ...

powder, which is converted to a

microcrystalline A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but ...

product when heated at about 1000 °C for 2 hours. The main reaction of the process is: :H₃BO₃ + H₃PO₄ → BPO₄ + 3 H₂O New ways of synthesizing the compound have also been reported, such as

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

and microwave synthesis. Due to the particular industrial interest of boron phosphate, other methods are used as well: *

Phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...

and triethyl borate *

Triethyl phosphate Triethyl phosphate is an organic chemical compound with the formula (C2H5)3PO4 or OP(OEt)3. It is a colorless liquid. It is the triester of ethanol and phosphoric acid and can be called "phosphoric acid, triethyl ester". Its primary uses are a ...

and

boron trichloride Boron trichloride is the inorganic compound with the formula BCl3. This colorless gas is a reagent in organic synthesis. It is highly reactive towards water. Production and structure Boron reacts with halogens to give the corresponding trihalides ...

Diammonium phosphate Diammonium phosphate (DAP; IUPAC name diammonium hydrogen phosphate; chemical formula (NH4)2(HPO4)) is one of a series of water- soluble ammonium phosphate salts that can be produced when ammonia reacts with phosphoric acid. Solid diammonium ph ...

acid and

borax The BORAX Experiments were a series of safety experiments on boiling water nuclear reactors conducted by Argonne National Laboratory in the 1950s and 1960s at the National Reactor Testing Station in eastern Idaho.

heated to 1000 °C *

Boric acid Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen orthoborate, trihydroxidoboron or boracic acid. It is usually encountered as colorless crystals or a white ...

and

phosphorus pentoxide Phosphorus pentoxide is a chemical compound with molecular formula Phosphorus, P4Oxygen, O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desic ...

(hydrothermal)

Structure

If obtained at pressure, the ordinary structure is isomorphous with the β-

cristobalite Cristobalite ( ) is a mineral polymorph of silica that is formed at very high temperatures. It has the same chemical formula as quartz, Si O2, but a distinct crystal structure. Both quartz and cristobalite are polymorphs with all the members o ...

, while subjecting it to high pressure is obtained a compound

isomorphic In mathematics, an isomorphism is a structure-preserving mapping or morphism between two structures of the same type that can be reversed by an inverse mapping. Two mathematical structures are isomorphic if an isomorphism exists between the ...

with α-

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

. The structure of AlPO₄, berlinite, is isomorphous with α-

Applications

It is used as a catalyst for

dehydration In physiology, dehydration is a lack of total body water that disrupts metabolic processes. It occurs when free water loss exceeds intake, often resulting from excessive sweating, health conditions, or inadequate consumption of water. Mild deh ...

and other reactions in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

. Also, it serves as a source of phosphates for

exchange reactions Exchange or exchanged may refer to: Arts, entertainment and media Film and television * Exchange (film), or ''Deep Trap'', 2015 South Korean psychological thriller * Exchanged (film), 2019 Peruvian fantasy comedy * Exchange (TV program), 2021 Sou ...

in the solid state to obtain metal phosphates.

References

{{Phosphates Boron compounds Phosphates