Barium pyrophosphate has the molecular formula of
Ba2P2O7 and the molecular weight of 448.5973 g/mol. It
has the CAS number of 13466-21-2 and may be prepared
by the solid-state reaction of the dibasic orthophosphate,
or alternately by the precipitation of a soluble Ba salt
with aqueous pyrophosphoric acid:
2Ba HPO4 + heat ? Ba2P2O7 +H2O
BaCl2 (aq) +H4P2O7 (aq) ? Ba2P2O7 (s) + 2HCl (aq)
The solution method produces a dihydrate,
Ba2P2O7·2H2O.
White powder. Soluble in acids and ammonium salts; very slightly soluble in water.
Ba2P2O7 is a promising phosphor host material, showing different emission properties upon doping with rare earth and other elements. Bi doped Ba2P2O7 crystals exhibit broadband NIR photoluminescence.