Research project Green coordination polymers for catalysis and medicine
Coordination polymers (CPs) and their porous analogues metal-organic frameworks (MOFs) are solid materials made of metal cations linked by organic molecules. These materials essentially behave as sponges with ordered nanometer sized pores and are capable of capturing, converting, and releasing target molecules such as pollutants.
The project aims to develop CPs and MOFs with a particular focus on high stability, biocompatibility and the use of renewable reagents. Biocompatible nontoxic metal cations like bismuth (Bi3+) and zirconium (Zr4+) are used in the project as the metal cations to form the CPs and MOFs. For the organic “linker” molecules in the CPs and MOFs, the project focuses on utilizing naturally organic molecules that are common in plant-based materials.
One of the MOFs developed in the project, named SU-101, was created by combining Bi3+ with the organic molecule ellagic acid. Ellagic acid is an edible antioxidant found in foods such as strawberries, raspberries, grapes, pomegranate, walnuts, as well as beverages such as wine and whiskey. Ellagic acid is one of the main building blocks of naturally occurring polyphenols - tannins. The MOF can made in a very simple and green process by stirring water, vinegar, ellagic acid (extracted from pomegranate peel or tree bark) and nonhazardous bismuth oxide at room temperature. SU-101 exhibited very high chemical stability and one of the highest uptakes of the pollutant hydrogen sulfide.