Role of Hydrogen-Bonded Interactions in the Crystal Packing of Phenylenediammonium Phosphomolybdates

Self-assembled synthesis of three new organic/inorganic hybrid solids (1−3) in the presence of isomeric
phenylenediammonium ions (p-, m-, and o-) demonstrates the role of nonbonding interactions in the construction of phosphomolybdate-based solid-state assemblies. In 1, crystal packing is dominated by two kinds of supramolecular assemblies:  an unusual pentadecameric
water cluster linked through p-phenylenediammonium (ppda) cations and a hydrogen-bonded assembly of a ppda cation with four
phosphomolybdate anions. In 2, a pair of m-phenylenediammonium (mpda) cations linked through π···π interactions envelops a
phosphomolybdate anion from either side through hydrogen bonding mediated by water molecules forming butterfly-like supramolecular
motifs. In 3, a new kind of O−W−O−W (organic−water) linker formed by alternate hydrogen bonding between o-phenylenediammonium (opda) and water molecules; such motifs are well decorated around a pentamolybdate cluster anion leading
to the formation of the three-dimensional architecture. Crystal structures of 1−3 reveal that supramolecular synthons earlier observed
between water and organic ammonium cations in the presence of octamolybdate anions are broken in the presence of
diphosphopentamolybdates due to the latter anion's strong affinity for hydrogen bonding with the cations.