Multiresponsive supramolecular systems for information processing at the molecular level

Abstract

Information processing at the molecular level requires systems able to move between several states under control of specific inputs. Flavylium salts (2-phenyl-1-benzopyrylium salts)analogues of naturally occurring anthocyanin dyes, are a versatile family of molecules that illustrates the multistate/multiresponsive concept. On the basis of the pH and light dependent network of chemical reactions of the flavylium network, different forms can be obtained by external stimuli exhibiting different properties. The research work developed in the framework of this PhD thesis aimed the synthesis and study of multiresponsive covalently linked supramolecular systems, based on a flavylium unit coupled redox-active and/or metal-complexing moieties. It is intended to increase the number of stimuli in the complex network of flavylium, including electrons and metal ions besides protons and photons (flavylium). In an initial study, two new benzopyrylium salts with directly attached metalcomplexing groups were synthesized and characterized (Chapter 2). The electrical stimulus was introduced with a viologen (Chapter 3) and finally redox- and photoactive units such as Ru(II)polypyridyl complexes (Chapter 4) are discussed. Regarding their possible applications as model compounds to optical memories, it is expected to achieve with these new systems a larger number of states, which allow increased functionality and versatility.