Abstract
The asymmetric unit of the title salt contains two symmetrically independent [PW12O40]3- polyoxoanions, six L-iso-leucinium (2S,3S) cations and nine solvent water molecules. The anion shows a classical α-Keggin structure, which consists of a central PO4 tetrahedron surrounded by four vertex-sharing W3O13 trimers. The cation is mono-protonated L-iso-leucine amino acid. Most of the N-H units and all O-H units of six cations are involved in hydrogen-bonding interactions as H-donors, and some of the terminal and bridged oxygen atoms of the anions and the carbonyl oxygen atoms of three cations act as H-acceptors. The water molecules are also involved in hydrogen-bonding interactions. The extensive intermolecular N-H…O and O-H…O hydrogen bonds make a three-dimensional hydrogen-bonded network in the crystal structure.
