A Highly Symmetric Ionic Crystal Constructed by Polyoxoniobates and Cobalt Complexes for Preferential Water Uptake over Alcohols.

An ionic crystal assembled by PNb12O40(VO)6 and tris(1,2-diaminopropane)cobalt complexes was hydrothermally isolated and structurally characterized by routine methods. The compound exhibits three-dimensional channels with a pore size of 3.68 Å × 2.30 Å and composed of hydrophilic oxygen atoms of polyanions and hydrophobic -CH3 groups of 1,2-diaminopropane ligands. With increasing vapor pressure, the compound shows preferable adsorption toward water over alcohols, and a gate-opening behavior was deduced from the water adsorption isotherm.