Barium diphosphate

Structural formula
Space group	Pnma (No. 62)
General
Surname	Barium diphosphate
other names	Barium pyrophosphate; Barium phosphate (ambiguous); Dibarium diphosphate;
Molecular formula	Ba 2 P 2 O 7
Brief description	white solid
External identifiers / databases
EC number	236-716-7
ECHA InfoCard	100.033.364
PubChem	166822
Wikidata	Q19274663
properties
Molar mass	448.60 g mol −1
Physical state	firmly
density	3.9 g cm −3
Melting point	1430 ° C
solubility	practically insoluble in water (88 mg l −1 at 20 ° C); soluble in concentrated acids;
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 302-332
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Barium diphosphate is an inorganic chemical compound of barium from the group of diphosphates .

Extraction and presentation

Barium diphosphate can be made from barium hydrogen phosphate by heating it to 900 ° C.

{\ displaystyle \ mathrm {2 \ BaHPO_ {4} \ {\ xrightarrow {900 \ ^ {\ circ} C}} \ Ba_ {2} P_ {2} O_ {7} + H_ {2} O \ uparrow}}

It is also possible to produce it by reacting water-soluble barium salts such as barium chloride with diphosphoric acid , the dihydrate being formed.

{\ displaystyle \ mathrm {BaCl_ {2} + H_ {4} P_ {2} O_ {7} \ longrightarrow Ba_ {2} P_ {2} O_ {7} +2 \ HCl}}

properties

Barium diphosphate is a white solid that is practically insoluble in water. It has an orthorhombic crystal structure with the space group Pnma (space group no. 62) . Template: room group / 62

use

Barium diphosphate is a promising phosphor material , which shows different emission properties after doping with rare earths and other elements. Barium diphosphate crystals doped with bismuth show broadband NIR photoluminescence. Barium diphosphate activated with titanium has been used in fluorescent lamps since 1953.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Richard C. Ropp: Encyclopedia of the Alkaline Earth Compounds . Newnes, 2012, ISBN 0-444-59553-8 , pp. 271 ( limited preview in Google Book search).
↑ ^a ^b ^c ^d ^e data sheet Barium pyrophosphate, powder, -200 mesh, 99.9% trace metals basis from Sigma-Aldrich , accessed on December 26, 2014 ( PDF ).
↑ E. Radomińska, T. Znamierowska, W. Szuszkiewicz: Phase equilibria in the system Rb ₃ PO ₄ -Ba ₃ (PO ₄ ) ₂ . In: Journal of Thermal Analysis and Calorimetry . 103, No. 2, 2011, pp. 761-766, doi : 10.1007 / s10973-010-0962-y .
^ Carla Heyward, Matthew Mann, Joseph Kolis: Hydrothermally synthesized α-Ba ₂ P ₂ O ₇ . In: Acta Crystallographica Section E Structure Reports Online. 66, No. 12, 2010, pp. I84-i84, doi : 10.1107 / S1600536810043527 .

[Richard_C._Ropp-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Richard C. Ropp: Encyclopedia of the Alkaline Earth Compounds . Newnes, 2012, ISBN 0-444-59553-8 , pp. 271 ( limited preview in Google Book search).

[Sigma-2] ↑ ^a ^b ^c ^d ^e data sheet Barium pyrophosphate, powder, -200 mesh, 99.9% trace metals basis from Sigma-Aldrich , accessed on December 26, 2014 ( PDF ).

[Radominska-3] E. Radomińska, T. Znamierowska, W. Szuszkiewicz: Phase equilibria in the system Rb ₃ PO ₄ -Ba ₃ (PO ₄ ) ₂ . In: Journal of Thermal Analysis and Calorimetry . 103, No. 2, 2011, pp. 761-766, doi : 10.1007 / s10973-010-0962-y .

[DOI10.1107/S1600536810043527-4] Carla Heyward, Matthew Mann, Joseph Kolis: Hydrothermally synthesized α-Ba ₂ P ₂ O ₇ . In: Acta Crystallographica Section E Structure Reports Online. 66, No. 12, 2010, pp. I84-i84, doi : 10.1107 / S1600536810043527 .