A research group led by Professor Masahisa Osawa (Department of Applied Chemistry) of Nippon Institute of Technology has succeeded in synthesizing a sensor material that selectively incorporates specific organic molecules and responds by changing the emission color.The mechanism by which the emission color changes was elucidated.This achievement was adopted on the back cover of "Dalton Transactions", which is the most prestigious journal of the Royal Society of Chemistry for Inorganic Chemistry.It will be posted following last year.
The research group is developing a sensor material whose emission color changes depending on external stimuli (grinding, contact with organic molecules, temperature (heat), etc.).In particular, the development of materials that can respond to specific organic molecules has been attracting attention and being actively studied from the viewpoint of molecular recognition.
This time, we aimed to chemically modify the organic ligand of the luminescent material to create a host space for molecular recognition (a part corresponding to a keyway when expressing high selectivity like a key and a keyway) between molecules. ..Chemical modification of conventional organic ligands with bulky tert-butyl groups has succeeded in creating hydrophobic spaces between molecules.Furthermore, when the ability to recognize various alkanes (aliphatic saturated hydrocarbons) using this space was tested, only normal hexane (alkanes with 6 carbon atoms) was taken into the space, and the emission color was strong and weak from green emission. It changed to orange emission.
Alkanes with 5 carbon atoms show strong green emission without being incorporated, but only samples with 7 carbon atoms hexane show weak orange emission.Structural analysis revealed that hexane is incorporated between the molecules and greatly distorts the structure of the luminescent molecule, resulting in a change in emission color.Alkanes with a branched structure were not taken in, demonstrating high selectivity.
In the future, we would like to work on the recognition of various organic molecules based on the molecular design guidelines shown this time.
