Reversible transformation between ionic liquids and coordination polymers by application of light and heat.

Reversible transformation between an ionic liquid and a coordination polymer by application of light and heat has been achieved. Ultraviolet light irradiation transforms the transparent liquid to a yellow solid; a reverse reaction occurs due to the application of heat. The transformation accompanies drastic switching of intra- and intermolecular coordination bonds of a ruthenium complex. This is a novel material conversion methodology that connects the fields of ionic liquids and coordination polymers.