Pentakis(l-prolinium) dodecatungstoborate trihydrate

The title polyoxometalate-based organic-inorganic hybrid compound, (C5H10NO2)5[BW12O40]·3H2O, consists of one α-Keggin-type [BW12O40]5− polyoxoanion, five crystallographically independent l-prolinium cations and three uncoordinated water molecules. The polyoxoanion shows characteristic features with respect to bond lengths and angles. Several N—H...O and O—H...O hydrogen bonds between the organic cations, inorganic anions and crystal water molecules lead to a three-dimensional supramolecular structure