Crystal-to-crystal transformations of a series of isostructural metal-organic frameworks with different sizes of ligated solvent molecules

Inorg Chem. 2013 Apr 1;52(7):3891-9. doi: 10.1021/ic302641v. Epub 2013 Mar 11.

Abstract

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 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.