Click/release reaction and SO₂ recycling for multichannel dynamic chiroptical materials

Constructing dynamic chiral materials via a combined covalent and non-covalent strategy remains an emerging and challenging task. Here, we report a unique example of this strategy using a specialized click-and-release reaction to create a multichannel dynamic chiroptical system. We utilize a highly efficient inverse electron demand Diels-Alder reaction between a chiral-moiety-grafted thiophene S,S-dioxide and a cyclooctyne. This reaction effectively disrupts a photoinduced electron transfer pathway, enabling a high quantum yield green fluorescence emission. Furthermore, the reaction occurs in-situ, inducing a structural evolution from nanospheres to vesicles or from micro-sheets to helical nanotubes, which in turn triggers the appearance of circularly polarized luminescence. Crucially, this click reaction releases a SO₂ molecule. By introducing a fluorescent dye, we are able to selectively capture the SO₂, which activates its red fluorescence and triggers an energy transfer from the green-emitting chromophore. This elegant design allows us to achieve dynamic control over a dual-channel chiroptical system, with independent green and red emissions, mediated synergistically by the click reaction and subsequent SO₂ recovery. The efficiency of this in-situ reaction within the aggregates, coupled with the high quantum yield of the products and the exceptional atom economy provided by byproduct recycling, offers a highly effective strategy for constructing chiral supramolecular materials via non-covalent assembly and covalent reaction.