Tunable Thermochromism of Multifunctional Charge-Transfer-Based Supramolecular Materials Assembled in Water

Stimuli-responsive materials, such as thermochromics, have found mass usage and profitability in manufacturing and process control. Imparting charge-transfer-based functional supramolecular materials with tunable thermochromism emerges as an ideal strategy to construct optically responsive multifunctional assemblies. Herein, the authors report a new series of thermochromic charge-transfer-based supramolecular materials assembled in water. These assemblies are composed of a bis-bipyridinium-derived acceptor and a series of commercially available donors—namely, the neurotransmitter melatonin and its analogue bioisosteres. When the chemical structure of the donors are tailored, the strength of the charge-transfer interactions can be tuned. Thermochromic aerogels and inks of these materials are prepared, with a large selection of colors, in environment-friendly solvents and demonstrate tunable thermochromic transition temperatures ranging from 45 to 105 °C. Favorable compatibility of these materials with comm...