Luminescence Properties Of β-Diketonate Complexes Encapsulated In The Channel Of Nanozeolite L

Europium(Ⅲ) β-diketonate complexes have the attractive luminescent properties suchas super light-absorbing capability, sharp emission lines, high color purity and bright color.However, low thermal and photochemical stability of europium(Ⅲ) β-diketonatecomplexes severely limit their full exploitation in a wide range of applications. Remarkableincrease of the stability of Europium(Ⅲ) β-diketonate complexes, encapsulated within thechannels of nanozeoliteL using“ship-in-a-bottle” procedure has been reported. Owing to thehydrolysis of trivalent europium ions, the acidity inside the channels increase. It is knownthat protonation of diketonates competes with full coordination to Eu3+and that incompletecoordination affects the luminescence yield. Ammonia have improved the luminescenceyield of ZL-based host-guest composites Ammonia escapes, however, quickly underambient conditions and the improvement is therefore not sustainable. However, the Eu3+doped zeolite show strong proton strength in the channels. It is therefore highly importantto improve the luminescence effiency of lanthanide complexes within zeolite L through asustainable way.Herein, we choose the organosilane-based imidazolium ionic liquid1as stopper forpreparing zeolite hybrid materials, because it bears a positively charged part which easilyenters the negatively charged NZL-channel upon exchanging a cation. Selectivemodification of ZL with stopper molecules can prevent penetration of small molecules thatwould otherwise enter the channels or it can prevent guests from leaving the host. Eachstopper attached to the channel entrance exchanges one of the cations that control theproton strength and improve the luminescence effiency. We further found that brightlyluminescent transparent films can be prepared from aqueous suspensions of the stopper-modified composites.