Signal processing with multicomponent systems based on metal complexes

Molecular-level systems that respond to external stimulation by changing some physical or chemical properties can be viewed as input–output devices and therefore may be useful for processing information. In recent years, several investigations on species capable of mimicking the function of macroscopic wires, switches, connectors, memories, logic gates, and circuits have been reported. The rational basis for this research stems from the fact that in living organisms information is transported, elaborated and stored by molecular or ionic substrates operating in a solution-based environment. Because of their diverse and valuable physico-chemical properties, metal complexes have been extensively used as functional components for the construction of artificial molecular devices capable of processing information. Here we illustrate recent progress, and discuss limitations and perspectives of this research area.