Control of Polymorphism of Metal–Organic Frameworks Using Mixed-Metal Approach

Abstract

Herein, we report the influence of iron(III) on the crystallization of chromium(III) terephthalate metal–organic framework. The selective phase formation of polymorphs MIL-101 and MIL-88B can be systematically controlled by varying the concentration of metal-cationic competitor, iron(III). The addition of iron(III) affects not only the selective phase formation but also the morphology and crystallinity of chromium(III) terephthalate MOF. This investigation clearly indicates the crystal growth tailoring of polymorphic MOFs by means of the second metal ionic competitor.