Final Report Summary - BOROMAT (Boronic acids as building blocks for construction of molecular nanostructures and polymeric materials)
In our project, we have investigated the self-assembly of boronic acids with other molecular building blocks. We could show that it is possible to synthesise new classes of boron-based compounds using multicomponent condensation reactions.
We successfully synthesised new borasiloxanes rings and we used them as building blocks in the construction of more complex structures. This has involved the introduction of different functionalities on the borasiloxane ring. We have shown that large organic macrocycles with borasiloxane and imine linkages are easily accessible in simple polycondensation reactions. We have also demonstrated that the macrocycles are best made by mechanochemical syntheses in a ball mill. Our work showed the utility of mechanochemistry in structural supramolecular chemistry. We have demonstrated that mechanochemical syntheses of borasiloxane macrocycles can be achieved with high yields, outperforming more classical solution-based methods.
We have continued our studies with the development of borylated clathrochelates as building blocks in supramolecular chemistry. Borylated clathrochelates complexes are very versatile building blocks with extremely high thermodynamic stability and kinetic inertness of the encapsulated metal ion, making them a suitable building block for construction of different large supramolecular structures and different Metal-organic frameworks (MOFs). We have successfully synthesised new clathrochelates units based on pyridine boronic acid. The dipyridyl clathrochelates ligands were further used for the construction of different supramolecular motifs by self-assembly with another metal ion. The unique feature of those new clathrochelates is the anionic charge of the ligand (to the best of our knowledge the first one reported to date). New polymeric networks have been synthesised and their porosity was determined by nitrogen adsorption measurements. The implications of this work are wider. We predict that clathrochelate-based building blocks will play an important role in future molecular nanoscience.
We successfully synthesised new borasiloxanes rings and we used them as building blocks in the construction of more complex structures. This has involved the introduction of different functionalities on the borasiloxane ring. We have shown that large organic macrocycles with borasiloxane and imine linkages are easily accessible in simple polycondensation reactions. We have also demonstrated that the macrocycles are best made by mechanochemical syntheses in a ball mill. Our work showed the utility of mechanochemistry in structural supramolecular chemistry. We have demonstrated that mechanochemical syntheses of borasiloxane macrocycles can be achieved with high yields, outperforming more classical solution-based methods.
We have continued our studies with the development of borylated clathrochelates as building blocks in supramolecular chemistry. Borylated clathrochelates complexes are very versatile building blocks with extremely high thermodynamic stability and kinetic inertness of the encapsulated metal ion, making them a suitable building block for construction of different large supramolecular structures and different Metal-organic frameworks (MOFs). We have successfully synthesised new clathrochelates units based on pyridine boronic acid. The dipyridyl clathrochelates ligands were further used for the construction of different supramolecular motifs by self-assembly with another metal ion. The unique feature of those new clathrochelates is the anionic charge of the ligand (to the best of our knowledge the first one reported to date). New polymeric networks have been synthesised and their porosity was determined by nitrogen adsorption measurements. The implications of this work are wider. We predict that clathrochelate-based building blocks will play an important role in future molecular nanoscience.