Novel expansion/shrinkage modulation of 2D layered MOF triggered by clathrate formation with CO2 molecules

Crystal-to-crystal transformation from a 3D interpenetrated-type MOF {[Cu(BF4)(2)(bpy)(H2O)(2)](bpy)}(1) to a 2D square-grid-type [Cu(BF4)(2)-(bpy)2](2)(bpy=4,4'-bipyridine) was observed. It was derived from dehydration and confirmed by in situ FT-IR, TG, and elemental analysis. Moreover, we elucidate the novel expansion/shrinkage dynamic modulation of 2 triggered by clathrate formation with gas molecules.