Photoluminescence Properties of Europium Complexes Encapsulated into MSBA-15

The Eu complexes-Eu (TTA)3phen (TTA: thenoyltrifluoroacetone, phen: 1,10-phenanthroline) were encapsulated, uniformly distributed into the channels of the modified SBA-15 (labeled with MSBA-15), and structurally characterized. The photoluminescence properties of the encapsulated complexes were systematically studied in contrast to the pure complexes. The results indicate that the excitation bands assigned to the π-π* electron transition of the ligands for Eu3+complexes in encapsulated complexes were split into different components, and the5D0-7F0transitions became partly allowed. The emission lines for the5D0-7F2transitions became broader and the relative intensity for different crystal field components varied greatly in comparison to the pure complex. Most importantly, the photostability and thermostability of the emissions improved considerably.

Purity and decomposition theorems for staggered sheaves

Two major results in the theory of ℓ-adic mixed constructible sheaves are the purity theorem (every simple perverse sheaf is pure) and the decomposition theorem (every pure object in the derived category is a direct sum of shifts of simple perverse sheaves). In this paper, we prove analogues of these results for coherent sheaves. Specifically, we work with staggered sheaves, which form the heart of a certain t-structure on the derived category of equivariant coherent sheaves. We prove, under some reasonable hypotheses, that every simple staggered sheaf is pure, and that every pure complex of coherent sheaves is a direct sum of shifts of simple staggered sheaves.

Improved Luminescence Properties of Europium Complexes Encapsulated into Mesoporous SBA-15

Two kinds of Eu3+ complexes—Eu(TTA)3(TPPO)2 (TTA: thenoyltrifluoroacetone, TPPO: triphenylphosphineoxide) and Eu(BA)3(TPPO)2 (BA: 1-benzoylacetone)—were fully encapsulated, uniformly distributed into the channels of unmodified and modified SBA-15, and structurally characterized. The luminescent properties of the encapsulated complexes were systematically studied in contrast to the pure complexes. The results indicate that the excitation bands assigned to the π–π* electron transition of the ligands for Eu3+ complexes encapsulated in SBA-15 were split into different components, and the 5D0-7F0 transitions became partly allowed. The emission lines for the 5D0-7F2 transitions became broader and the relative intensity for different crystal field components varied greatly in comparison to the pure complex. Most importantly, the photostability and thermostability of the emissions improved considerably.