Crystal-to-Crystal Transformations of a Series of Isostructural Metal–Organic Frameworks with Different Sizes of Ligated Solvent Molecules

Isostructural 3D metal–organic frameworks (MOFs) [Zn₂(BTC)­(NO₃)­S₃] [where BTC = 1,3,5-benzenetricarboxylate; S = EtOH (<b>1</b>), DMF (<b>2</b>), DMA (<b>3</b>), or DEF (<b>4</b>)] of a 3-connected <b>srs</b> net topology have been prepared in the presence of serine as a template. The MOFs show different framework stabilities depending on the sizes of the ligated solvent molecules and undergo a crystal-to-crystal transformation at ambient conditions into a 1D chain structure either directly or via different types of intermediates depending on the ligated solvent molecules and the sample handling conditions. A single crystal of the MOF with the ligated DMF molecules, [Zn₂(BTC)­(NO₃)­(DMF)₃] (<b>2</b>), is stable in Mg^II- and Co^II-DMF solutions; however, it transforms into a single particle-like microcrystalline aggregate of Cu-HKUST-1 in a Cu^II-DMF solution