Bio-inspired multistate networks responsive to light, pH and thermal inputs - An example of a multistate system operating through different algorithms

Two multistate networks based on 4′-acetamidoflavylium and 4′-aminoflavylium, possessing six- and sevenfold multistates, respectively, and that can be reversibly interchanged by inputs of light, pH jumps and heat, are characterized. The two networks are connected irreversibly, the 4′-acetamidoflavylium being transformable into the 4′-aminoflavylium by means of a heat input in extremely acidic solutions. The possibility of performing several different write-read-erase cycles, as models for optical memories operating by different algorithms, is discussed. An upper level of operation of these photochromic devices in which the algorithms are used as inputs to switch between the several memory cycles is proposed.