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 (1), DMF (2), DMA (3), or DEF (4)] of a 3-connected srs 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] (2), is stable
in MgII- and CoII-DMF solutions; however, it
transforms into a single particle-like microcrystalline aggregate
of Cu-HKUST-1 in a CuII-DMF solution.