Physics and Chemistry make progress in the study of synthetic stimulus-responsive fluorescent macrocycles

[ Instrument Network Instrument R & D ] Functional macrocyclic molecules have always played a very important role in the field of supramolecular chemistry. The design and synthesis of new stimulus-responsive macrocyclic compounds is expected to show broad application prospects in intelligent materials and other fields. Recently, the team of Cong Huan, a researcher at the Research Center for Supramolecular Photochemistry, Institute of Physics and Chemistry, Chinese Academy of Sciences, reported a new type of fluorescent bimacrocyclic compound, Bowtie Arene.

Researchers first achieved the coupling of tetrastyrene units and aryl bromide side chain units through a coupling reaction. The coupling products and paraformaldehyde were reacted by Lewis acid catalysis to quickly synthesize bowtie aromatic hydrocarbon molecules. The X-ray single crystal structure of the molecule shows that its geometry resembles a bow tie, with a symmetrical double columnar large ring cavity, and almost the same shape and size as the column [5] arene.

Bow tie aromatics have significantly different fluorescence properties in the crystalline state and in different ratios of tetrahydrofuran / water mixed solvents. Experimental and theoretical calculations reveal that the fluorescence properties of the molecule are closely related to the molecular stacking state. Combining the fluorescent discoloration properties of the molecules and the steam adsorption properties of the macrocyclic molecules, the bowtie aromatics further show the ability to force and discolor: the disordered powder obtained after mechanical grinding can be further induced by xylene vapor fumigation The molecules are stacked again in order to achieve the disordered-ordered stacking state and the corresponding switching of fluorescence properties.

In view of the important potential applications of fluorescent macrocyclic compounds in the fields of molecular sensing, cell imaging, and data security, the development of bowtie aromatics is expected to provide new innovation opportunities in these areas. Related work was published in "Angewandte Chemie International Edition" and was selected as a VIP article. The first author of this work was Lei Shengnan, a PhD student of the Institute of Physics and Chemistry, and Zeng Yi, a researcher at the Institute of Physics and Chemistry, and Xiao Hongyan, an associate researcher, assisted in photophysical testing and theoretical luminescence calculation. The research work was funded by the Fund Committee, the Chinese Academy of Sciences, the National Key Research and Development Plan and the Director of the Institute of Physics and Chemistry.