Novel Highly Luminescent Amine-Functionalized Bridged Silsesquioxanes

作者：Pereira Rui F P; Nunes Silvia C; Toquer Guillaume; Cardoso Marita A; Valente Artur J M; Ferro Marta C; Silva Maria M; Carlos Luis D; Ferreira Rute A S; Bermudez Veronica de Zea

来源：Frontiers in Chemistry, 2018, 5: 131.

DOI：10.3389/fchem.2017.00131

• bis[(3-trimethoxysilyl) propyl] amine
• sol-gel chemistry
• solvent-assisted structuring
• morphology
• luminescence

Amine-functionalized bridged silsesquioxanes (BSs) were synthesized from bis[(3-trimethoxysilyl) propyl] amine via a solvent-mediated route. BS-1 and BS-2 were obtained at neutral pH with sub-and stoichiometric amounts of water, respectively, and high tetrahydrofuran content. BS-3 was prepared with hyperstoichiometric water concentration, high tetrahydrofuran content, and hydrochloric acid. BS-4 was synthesized with hyperstoichiometric water concentration, high ethanol content, and sodium hydroxide. BS-1 and BS-2 were produced as transparent films, whereas BS-3 and BS-4 formed white powders. Face-to-face stacking of flat or folded lamellae yielded quasi-hydrophobic platelets with emission quantum yields of 0.05 +/- 0.01 (BS-1 and BS-2) or superhydrophilic onion-like nanoparticles with exciting emission quantum yields of 0.38 +/- 0.03 (BS-3) and 0.33 +/- 0.04 (BS-4), respectively. The latter two values are the largest ever reported for amine-functionalized siloxane-based hybrids lacking aromatic groups. Fast Grotthus proton hopping between = NH2+/= NH groups (BS-3) and = N-/= NH groups (BS-4), promoted by H+ and OH- ions, respectively, and aided by short amine-amine contacts provided by the onion-like morphology, account for this unique optical behavior.

• 出版日期2018-1-15
• 单位中国地震局