Complex-bearing Metal-Organic Frameworks: Snapshots of Reactions

Lead Research Organisation: University of Nottingham
Department Name: Sch of Chemistry

Abstract

The ability to precisely determine molecular structure lies at the heart of chemistry. Often, understanding the structure of a molecule gives invaluable insight into the properties and reactivity of that molecule. However, many reactions proceed so rapidly that the determination of the three-dimensional structure of a molecule, particularly short-lived intermediates, can be enormously challenging if not impossible using conventional approaches. For many years single crystal X-ray diffraction has provided the primary methodology for determining molecular structure, but the technique is limited by the requirement for a single crystal, a crystal without, or nearly without, flaws. It is not always possible to obtain a single crystal of some molecular species, for example if a compound is highly reactive, produced in small quantities or simply does not adopt the well-ordered arrangements required for single crystals. This proposal seeks to address these issues.

We will use metal-organic frameworks (MOFs), framework structures that provide ordered structural arrangements of molecular building-blocks, as a platform for trapping and supporting metal complexes that are able to undergo subsequent reactions - all in a crystalline phase. It is possible to prepare such systems such that metal complexes, including systems that mimic compounds used in catalytic processes, sit upon the struts of the framework and are positioned next to channels that allow transport of reagents to the reactive metal site. The supported complexes can then undergo reactions without losing the overall crystallinity of the framework, allowing determination of the structure of the products. As the reactive site is protected from other molecules, embedded with the framework structure, it is possible to control which molecules are introduced to the reactive framework-supported complex and to preclude reactive sites coming together. In this way it is possible to effectively trap reactive species within the framework, allowing determination of their structures. This project will develop this strategy providing us with a method to take 'snapshots' of molecular reactions.

Planned Impact

Our research directly addresses the topic of directed assembly of extended framework structures and their use in new chemistry and new materials. Therefore, our studies lie directly at the heart of the EPSRC Grand Challenge in Directed Assembly of Extended Structures with Targeted Properties, which envisages an increasingly important role for self-assembly approaches in the manufacture of new functional materials. EPSRC recognise that the time scale for these developments is uncertain and may require 20 years or even more to reach full maturity. However, we anticipate that as we develop and communicate the effectiveness of the strategy for studying reactions within complex-bearing MOFs, our approach will be taken up widely. More importantly we believe that collaborations between those directly using our approach and synthetic chemists will be become increasingly important, leading to widespread uptake of complex-bearing MOFs as a tool for elucidating and understanding reaction processes at metal complexes. We anticipate that insights into reaction processes will have short term impact on academic researchers and increasingly in the research laboratories of large companies. We will seek to develop and exploit the impact of our research through the organization of a multi-disciplinary one-day meeting for both academic and industrial parties interested in the development of this research field and the emergent strategies that we seek to develop.


The PI has a strong track record in communicating his science to wider audiences, in using the media to publicise his research and in presenting the case for science to policymakers. We believe that the proposed research is ideal for public communication and will bid to present our research at the Royal Society Exhibition in the last year of the project. A major impact from the research will be the output of trained researchers, 2 postdocs and 2 PhD students, whose training will be enhanced through their participation in a project that involves exciting international collaborations. This cohort of researchers will provide a highly significant impact, beyond the timescale of the project, through the availability of highly skilled-researchers who will support an expansion of research using tailored extended framework structures to gain insight into reaction processes. Any results of commercial significance that arise, possibly related to synthetic methodology, will be protected through the Business Partnership Unit (BPU) within the School of Chemistry at Nottingham.

Publications

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