Hydrogen bond-regulated microporous nature of copper complex-assembled microcrystals

A Cu complex-assembled compound [Cu(bpy)(BF4)2(H2O)2·(bpy)]n (bpy=4,4′-bipyridine) with non-interpenetrated structure was synthesized and its adsorption properties for N2, Ar, and CO2 were studied. The adsorption of gas on this complex suddenly begins at a definite relative pressure (`gate pressureʹ) regardless of almost nil adsorption below the gate pressure. Such a unique adsorption phenomenon is attributed to the hydrogen bond-regulated microporous nature of this complex; hydrogen bonds in pores block adsorption below the gate pressure. Additionally, the gate pressure depends on both the adsorbate and the pretreatment temperature of the Cu complex solid.