Syntheses,structures and properties of three neutral bisupporting heteropolyoxometalates

Three neutral polyoxometalates [PVW₁₁O₄₀{M(phen)₂H₂O}₂] · 3H₂O (phen = 1,10′-phenanthroline, M=Co 1, Zn 2, Ni 3) are composed of water and the neutral Keggin-type polyoxometallate covalently linking a pair of transition metal complex fragments on opposite sides. The transition metal lies in the center of a distorted octahedron. Multi hydrogen-bonding interactions between coordinated waters of neutral polyoxometalate molecules and terminal oxygen atoms of Keggin units and between bridging oxygens of Keggin units and lattice water create a two dimensional layer and between the layers there exist van der Waals forces. The framework of the neutral molecule begins to decompose at ca 500°C. Compound 1 exhibits a weak antiferromagnetic interaction in the 2–300 K range.