Synthesis and structure determination of tetrakis(4-iodoanilinum) β-octamolybdate dihydrate

Tetrakis(4-iodoanilinum) β-octamolybdate dihydrate (I) was synthesized and its structure was solved using powder diffraction methods and the atoms positions optimized by the solid state DFT calculations. The structure is triclinic (P-1) with cell parameters: a = 9.7099(4) Å, b = 9.8169(3) Å, c = 14.9842(6) Å, α = 97.349(3)°, β = 102.989(3)°, γ = 113.335(3)°, V = 1239.79 Å3. The anion type was determined based on Patterson map analysis and the presence and location of water molecules were determined based on the locations of solvent accessible voids in the structure and confirmed with molecular dynamics calculations and high temperature IR spectroscopy. ure of (I) consists of molybdenum–oxygen clusters, protonated amine and water molecules. Each cluster consists of eight distorted MoO6 octahedra sharing corners and edges forming β-[Mo8O26]4− anions. Protonated 4-iodoanilinum cations form, apart from electrostatic attraction, moderately strong NH⋯O hydrogen bonds binding these molecules to the oxygen atoms in Mo8O26 clusters. In addition, one of the amine molecules form a weak OH⋯I bond with the water molecule, which is loosely bound with a weak OH⋯O hydrogen bond to molybdenum–oxygen cluster.