Finely Controlled Circularly Polarized Luminescence of a Mechano‐Responsive Supramolecular Polymer

Abstract

We report on finely controlled circularly polarized luminescence (CPL) supramolecular polymerization based on a tetraphenylethene core with four L ‐ or D ‐alanine branch side chains (L ‐ 1 and D ‐ 1 ) in the solution state resulting from the tuning of mechanical stimulus. Weak, green emissions of L ‐ 1 and D ‐ 1 in tetrahydrofuran (THF) were converted to strong blue emissions by tuning the mechanical stimulus. The strong blue emissions were caused by an aggregation‐induced emission (AIE) effect during the formation of a supramolecular polymer. Lag time in the supramolecular polymerization was drastically reduced by the mechanical stimulus, which was indicative of the acceleration of the supramolecular polymerization. Interestingly, a significant enhancement of circular dichronism (CD) and CPL signals of the L ‐ 1 and D ‐ 1 was observed by tuning the rotational speed of the mechanical stimulus, which implies that the chiral supramolecular polymerization was accelerated by the mechanical stimulus. These results imply that the CPL signals were tuned by the strength of the external mechanical stimulus.