engleski

Selective Mechanochemistry: Flexible Molecular Receptors for Recognition of Organic Isomers in Milling Processes

Molecular recognition, a process which emerges from weak non-covalent interactions, is of paramount importance in the chemistry of life and also for the design of functional supramolecular systems. Selective molecular recognition is traditionally performed in solution, where the host and guest have mobility to come close and to interact. However, recent advances in the field of mechanochemistry have shown that various concepts of supramolecular chemistry can be used also for solvent-free reactions. Herein we present flexible polyamine host(L) which recognizes and selectively binds maleic acid during the milling with solid mixtures where the fumaric acid or other investigated competitors were present in large excess. During the recognition, L adapts its conformation and forms specific complex with each of the six investigated dicarboxylic acids, regardless of whether the reaction was conducted in solution or in the solid state. Recognition via mechanochemistry involves intermediate phases, resulting with the same selectivity as achieved by crystallisation from solution. Milling techniques circumvent limitations of solution-based separation, as evidenced by facile binding of poorly soluble guests, while at the same time providing enough energy and mobility to the host and guest molecules required for selective recognition. Taken together, these results indicate a great potential of molecular recognition in the solid state for separation purposes.

Mechanochemistry ; Molecular recognition ; Selective binding ; Organic isomers

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