Solvent- and Vapor-Mediated Solid-State Transformations in 1,3,5-Benzenetricarboxylate Metal–Organic Frameworks

The reaction of 1,3,5-benzenetricarboxylic acid (H3BTRI) with ZnSO4·7H2O in DMF and H2O afforded [Zn2(μ2-OH2)­(HBTRI)­(BTRI)­(H2O)2]·DMA·3H2O (1). Compound 1 displays self-healing properties upon dehydration and rehydration as revealed by scanning electron microscopy. Further studies showed that 1 is flexible and able to absorb additional water molecules in high vapor pressure environments. The reaction of H3BTRI with Gd­(NO3)3·6H2O in DMF and H2O resulted in [Gd­(BTRI)­(H2O)6] (2). It is also possible to form compound 2 through a solid-state process when crystals of 1 are placed into a solution of Gd­(NO3)3·6H2O in DMF and H2O. The reverse process does not occur.