Direct Evidence for Single-Crystal to Single-Crystal Switching of Degree of Interpenetration in a Metal–Organic Framework

A known doubly interpenetrated metal–organic framework with the formula [Zn2(ndc)2(bpy)] possesses minimal porosity when activated. We show not only that the material converts to its triply interpenetrated analogue upon desolvation, but also that the transformation occurs in a single-crystal to single-crystal manner under ambient conditions. The mechanism proposed for the conversion is supported by computational methods and by analogy with the solid-state behavior of an analogous system.