Straightforward Synthesis of Single-Crystalline and Redox-Active Cr(II)-carboxylate MOFs

We report on a facile and environmentally friendly synthetic approach for single-crystalline chromium(II) carboxylate metal–organic frameworks (i.e., Cr 3 (BTC) 2 ·3H 2 O ( 1 ) and Cr(hfipbb)·H 2 O ( 2 ) at room temperature in water. Both MOFs can be easily dehydrated, affording single-crystalline materials with open Cr(II) sites. In addition, the redox activity and porosity of the resulting Cr(II) MOFs were examined.