Immobilized calixarenes and calixarene-related compounds are produced by a process comprising either:

• (a) contacting the calixarene or calixarene-related compound with a substrate containing one or more metallic or non-metallic oxides that has been surface modified by reaction with one or more polyhalides and/or polyalkoxides of an element capable of forming a stable aryloxide species with the substrate, or
• (b) reaction of such a substrate with a calixarene or calixarene-related compound that has been previously modified or derivatized by reaction with said polyhalides and/or polyalkoxides.