Chemical transformations of materials through the utilization of organometallic chemistry has been of fundamental importance both in the academic and industrial world for many decades. Owed in part to the vast array of tunable ligand environments surrounding catalytically active centers, a diverse array of applications has been developed. On the industrial scale, the chemical transformations for the synthesis of ammonia, synthesis gas, epoxyethane, sulfuric acid, nitric acid, and many polymer-based plastics involve an organometallic catalyst (iron, nickel, silver on alumina, vanadium, platinum & rhodium, and titanium respectively). For example, it is estimated that over 300 million tons of polymer-based plastics alone are synthesized annually. Most of these plastics involve organometallic catalysts in at least part of the synthesis. It is thus not surprising that many of the products we use in daily life undergo a chemical transformation by an organometallic catalyst. Due to the direct impact on our daily life, it comes as no surprise then that this area of study continues to develop new and diverse approaches for improvements in the chemical transformations and product development. One such approach for improving organometallic catalysts is through the incorporation of Metal-Organic Frameworks (MOFs) as designer catalytic materials.
MOFs are considered to be designer materials for catalytic reactions in part due to the diverse tunability, high stability, and the versatility of the structures. They are highly porous materials with immense surface areas and can be tuned for chiral or stereospecific reactions. Both the organic linker and metal center nodes can be tuned for catalytic reactions adding to the appeal of these materials as catalysts. As the study of MOFs has only been around since the late 1990’s, this field of study is still in its infancy in comparison to other catalytic approaches. Even though it is a relatively recent addition to catalytic chemistry, many MOFs have already been demonstrated to be remarkable organometallic catalysts. As such, utilizing MOFs for catalytic applications is seen as an approach that has a lot of untapped potential.
Chemical transformations by MOFs can be divided into two main categories: transformations by functionalized organic linkers and transformations by metal clusters. We envision that the future of organometallic chemistry might focus on the expansion of traditional organometallic chemistry to porous materials area by integrating porous materials such as MOFs with organometallic chemistry. For example, due to the high surface area and versatility of these structures, MOFs can be utilized as designer catalysts in organometallic transformations for a variety of applications. From the utilization of the linkers within the framework as site specific catalysts for designed reactions, an understanding of the impact of ligand sterics and electronics to the catalytic metal center can be observed and ultimately tuned. By observing homogeneous and heterogeneous reactions of metal cluster organometallic chemistry, an understanding of multi-metal catalytic reactions can be obtained. As a result of the knowledge gained in regard to both ligand-based and cluster-based MOF organometallic chemistry, these materials have begun to show promising results for traditional organometallic reactions as well as non-traditional applications. The applications and strategies for accomplishing organometallic chemistry utilizing a MOF material demonstrate some of the ways that researchers think about MOF chemistry in regards to catalytic applications.