Eu3+@PMO: synthesis, characterization and luminescence properties

Abstract

A periodic mesoporous organosilica (PMO) functionalized with dipyridyl-dihydropyridazine units has been successfully prepared by a hetero Diels–Alder reaction between the double bonds of an ethenylene-bridged PMO material and a substituted tetrazine. The ordering and mesoporosity of the parent material is maintained after the post-modification process, and the surface Diels–Alder adducts are clearly observable in the pores. These dipyridyl-dihydropyridazine moieties can form interesting chelates with lanthanide ions. Thus, two novel organic–inorganic luminescent hybrid materials have been obtained by linking of Eu³⁺ compounds to an ethene-PMO functionalized with dipyridyl-dihydropyridazine. Both materials have been studied in depth by photoluminescence spectroscopy and luminescence decay time measurements. Our results reveal the key role of surface Diels–Alder adducts as suitable sensitizing ligands for europium ions.