Eu3+@ PMO: synthesis, characterization and luminescence properties

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.