Near-Infrared Electrochromic and Chiroptical Switching Materials: Design, Synthesis, and Characterization of Chiral Organogels Containing Stacked Naphthalene Diimide Chromophores

Chiroptical switching materials in the visible and near-infrared spectral regions have been realized using a low molecular weight gel as a chiral scaffold and electrochromic chromophores as a stimulus-responsive trigger and operate as a result of the change in the electronic states of the chromophores within the chiral gel. N,N'-Bis(4-phenyl-2.3,4,6-tetra-O-acetyl-beta-D-glucopyranoside)-1,4,5,8-naphthale- netetracarboxylic diiinicle, synthesized by irniclization of 1.4,5,8-ii iphilialciieteti- tc irboxylic dianhydride with a sugar-bearing amine, call form stable chiral gels at room temperature. The redox-active gels exhibited reversible and drastic changes in circular dichroism in the visible and near-infrared spectral region between the three redox states (neutral, radical anion, dianion) of the naphthalene diimide chromophore. A large circular dichroism at 1310-1550 nm was induced when the stacked naphthalene diimide chromophores in the chiral gels were reduced to the radical anion state.