It's quite logical

A covalently bonded, as opposed to supramolecular, molecule incorporates several functionalities that can, under light control, carry out 13 logical operations. Each operation has been implemented before in separate molecules. However, by using different wavelengths of light, the developers can carry out the different operations separately or in combinations. Both the input and output are light, rather than electrochemical, pH, or other chemical and physical changes. The team suggests that building a molecular computer using this kind of component might never be achieved, but such molecules could be used in nanosensor and diagnostics devices.