Recyclable calix[4]arene-lanthanoid luminescent hybrid materials with color-tuning and color-switching properties

Inorganic–organic hybrid materials combine the properties of both components providing functionality with a wide range of potential applications. Phase segregation of the inorganic and organic components is a common challenge in these systems, which is overcome here by copolymerizing a metal-free calixarene ionophore and methyl methacrylate. A lanthanoid ion is then added using a swelling–deswelling procedure. The resulting luminescent hybrid materials can be made to emit any required color, including white light, by loading with an appropriate mixture of lanthanoids. The gradation of the emitted color can also be finely adjusted by changing the excitation wavelength. The polymer monolith can be recycled to emit a different color by swelling with a solution containing a different lanthanoid ion. This methodology is flexible and has the potential to be extended to many different ionophores and polymer matrices.