Kinetic and energetic insights in the dissipative non-equilibrium operation of an autonomous light-powered supramolecular pump

Natural and artificial autonomous molecular machines operate by constantly dissipating energy coming from an external source to maintain a non-equilibrium state. The in-depth study of these dissipative states is highly challenging as they exist only as long as energy is provided. Here we report on the detailed physicochemical characterization of the dissipative operation of a supramolecular pump transducing light energy into chemical energy by shifting the equilibrium of self-assembly reactions. The composition of the system under light irradiation was followed in real-time by 1H NMR and parameters such as the dissipation and the energy storage at the steady state were extracted for four different irradiation intensities. For the first time in an artificial system, we quantitatively probed the relationship between the light energy input and the deviation of the dissipative state from thermodynamic equilibrium. Our results also provide a testing ground for newly developed theoretical models.