The title compound, bis(piperazine-1,4-diylium) bis-(phenylphosphonato
)- 1kO,2:3k(2)O',4:5k(2)O'';1:2k(2)O,3:4- '-penta-mu-oxo-1:2k(2)O;1:5k
(2)O;2:3k(2)O;3:4k(2)- O;4:5k(2)O-decaoxo-1 )O,2k(2)O,3k(2)O,4k(2)O,5k
(2)O-pentamolybdenum(4-) dihydrate, (C4H12N2)(2)[Mo5O15(C6H5-O3P)(2)].
2H(2)O, contains isolated five-unit rings of vertex- and edge-sharing
distorted octahedral MoO6 units, doubly capped by PC6H5 entities (as [
PO3C6H5](2-)phenylphosphonate groups), To result in [(MoO3)(5-){(C6H5)
PO3}(2)](4-) {or [Mo5P2O21(C6H5)(2)](4-)} anions. Doubly protonated pi
perazinium cations and water molecules complete the structure.