Processing Chemical and Photonic Signals by Artificial Multicomponent Molecular Systems

Miniaturization has been an essential ingredient in the outstanding progress of information technology over the past fifty years. The next, perhaps ultimate, limit of miniaturization is that of molecules, which are the smallest entities with definite size, shape, and properties. 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 transferring, processing, and storing information. Some of these nanoscale devices can, in fact, perform logic operations of remarkable complexity. This research — although far from being transferred into technology — is attracting interest, since the nanometer realm seems to be out of reach for the “top-down” techniques currently available to microelectronics industry. Leaving aside futuristic speculations related to the construction of a chemical computer, molecular logic devices could be interesting for specific applications in areas such as diagnostics, medicine, and materials science, where problems need to be addressed in places — for example, inside a cell — that are out of reach for a silicon-based computer. Here we discuss the idea of processing information with artificial multicomponent molecular systems in solution by illustrating a few recent examples developed in our laboratory.