Scientists of Tomsk Polytechnic University have obtained a noncovalent organic framework (nCOF) based on zwitterionic iodonium salts. The zwitterionic iodonium salts have first been applied as a structural unit for forming a framework, which showed high stability and water absorption/desorption capacity. The research findings were published in the Chemical Science academic journal Q1, IF:9,346).
Obtaining the nCOFs is a continuation of a series of research works to synthetize diaryliodonium salts and their further application in materials chemistry. The research work was conducted by the scientists of the TPU Research School of Chemistry and Applied Biomedical Sciences jointly with their colleagues from universities in the USA, Great Britain, Japan and Saint Petersburg. The zwitterionic iodonium salts themselves are irreplaceable reagents in the synthesis of complex natural compounds and applied for the functionalization of organic molecules.
To obtain the nCOFs, the research team synthetized the zwitterionic iodonium salt. The zwitterionic iodonium salts are distinguished by the fact that they are neutral in general, however, at the same moment, they obtain positively and negatively charged fragments. Such a structure allows molecules to form supramolecular structures of a complex structure, however, the formation of porous structures has not been detected yet.
“In our conducted experiment, zwitterionic iodonium salts were used as donors or the sources of halogen bonds. A positively charged particle of one molecule interacts with a negatively charged fragment of the other one forming a polymeric spatial structure, which is similar to a honeycomb, i.e. a nCOF,”
says Natalia Soldatova, associate professor of the TPU Research School of Chemistry and Applied Biomedical Sciences and one author of the article.
The nCOFs obtained with the application of the zwitterionic iodonium salts possess the two features: stability and reversible sorption capacity. nCOF stability is provided by halogen bonds.
“The nCOFs based on the zwitterionic iodonium salts are promising materials for engineering and technology. Chemistry of these compounds are at their early stages and their development will definitely attract a lot of scientists’ attraction,” Pavel Postnikov, associate professor of the TPU Research School of Chemistry and Applied Biomedical Sciences and a head of the research project, comments the project’s prospects.
The research was carried out with the support of the Russian Science Foundation in the Laboratory for Non-Bonded Interactions in Materials Chemistry arranged and driven by the Decree No. 220 issued by the Government of the Russian Federation.