Continuous Processes for Chemical Separation Based upon Coordination Cages

• Applicant: Dr. Amit Ghosh
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 491225869

The dual challenges of global warming and limited oil supplies mean that petroleum cannot continue to be burned as fuel. Instead, the future of crude oil will be as a feedstock for separation into useful building blocks for chemical synthesis. To accelerate this transition, it is desirable to develop new, low-energy methods of chemical separation of both individual molecules and collections of molecules from petroleum. The industry also requires the efficient and economical purification of desired species from similar molecules during various processes. Moreover, crude oil contains compounds that are simultaneously harmful to the environment and technologically useful. Current oil refining processes may release some carcinogenic, mutagenic, and teratogenic, compounds into the environment. There is thus a need for their isolation both to minimize their pollutive impact and so that they may be used as chemical feedstocks.To solve those practical problems, new chemical separation strategies are required that are efficient and less energetically costly than those currently employed. This project will utilize the prior expertise of the Nitschke and co-workers (the host group) to develop a new means of separation of useful building blocks from crude oil, bio-feedstocks, and natural product mixtures. Metal-organic coordination cages provide new opportunities to address the need for improved separation technologies. Recent work in this field has demonstrated that these containers can encapsulate specific guest species and act as vehicles for targeted molecular transport and separation. The main objective of this proposed project is to explore the physical stimuli of light and heat to develop systems that are capable of continuous chemical separation.At first, water-soluble tetrahedron coordination cages M4L6 with thermoresponsive glyceryl and photoresponsive spiropyran units will be prepared by self-assembly of subcomponents with metal(II) ions (WP1). Next in WP2, the zwitterionic merocyanine units of the cage will be transformed to the closed spiropyran form by light, to solubilize the cage to an organic phase containing the feedstock. Simultaneously, these cages will be investigated for thermally controlled guest uptake and release. The final theme (WP4) of the project will bring together the new knowledge gained in WP2 and WP3 to develop systems that are capable of continuous chemical separation with orthogonal ‘clean’ stimulus.

• DFG Programme: WBP Fellowship
• International Connection: United Kingdom
• Host: Professor Dr. Jonathan R. Nitschke