The solutions of rare earth complexes Sm(Phen) 2(TTA)(Bipy)(NO 3) 3 and Sm(L) x (TTA) 4-x (NO 3) 3 [L=Phen (1,10-phenanthroline) or Bipy(2,2′-bipyridine), x =4, 3, 2, 1, 0; TTA is 2-thenoyltrifluoacetone] in EtOH(1&#...The solutions of rare earth complexes Sm(Phen) 2(TTA)(Bipy)(NO 3) 3 and Sm(L) x (TTA) 4-x (NO 3) 3 [L=Phen (1,10-phenanthroline) or Bipy(2,2′-bipyridine), x =4, 3, 2, 1, 0; TTA is 2-thenoyltrifluoacetone] in EtOH(1×10 -3 mol/L) were prepared. The coefficients of antenna effect are 31 5, 18 2 and 5 6 for Phen, Bipy and TTA, respectively, when the electron configuration of the excited state of the samarium atom in the complexes is 4 D 1/2 . The fluorescent intensity and the lifetime of the supramolecular encapsulation products of (CH 3) 3Si-MCM-41 and Sm 3+ complexes are stronger and longer than those of the encapsulation products of MCM-41 and Sm 3+ complexes respectively. The results show that the host with lipophilic channels is more favourable to the fluorescence of the rare earth complexes than the hydrophilic mesoporous molecular sieve. The fluorescent intensity of (CH 3) 3Si-MCM-41-Sm(Phen) 3(TTA)(NO 3) 3 is the strongest \{among\} the encapsulation series of Sm 3+ complexes, which is assumed to result from the greatly reduction of SiO-H vibration relaxation in host (CH 3) 3Si-MCM-41 and the presence of the discrete strong luminescent centres of the guest molecules associated with the nanosized material′s structure. The luminescent decay halftime of the supramolecular materials is much shorter than that of the powder of the samarium complexes. The result shows that the ligand transferring energy from the triplet state to the singlet state of Sm 3+ ( T 1→S , intersystem crossing) becomes higher. The fluorescent experimental results indicate that the interaction between the host and the guest influences the luminescent properties of the nanostructured supramolecular materials.展开更多
基金Supported by the Science Foundation of Guangzhou City( 2 0 0 0 - Z- 0 76 - 0 1),L aboratory of Rare Earth Chemistry andPhysics,Changchun Institution of Applied Chemistry,Chinese Academ y of Sciences and Key L aboratory of Inorganic Synthe-sis and Pr
文摘The solutions of rare earth complexes Sm(Phen) 2(TTA)(Bipy)(NO 3) 3 and Sm(L) x (TTA) 4-x (NO 3) 3 [L=Phen (1,10-phenanthroline) or Bipy(2,2′-bipyridine), x =4, 3, 2, 1, 0; TTA is 2-thenoyltrifluoacetone] in EtOH(1×10 -3 mol/L) were prepared. The coefficients of antenna effect are 31 5, 18 2 and 5 6 for Phen, Bipy and TTA, respectively, when the electron configuration of the excited state of the samarium atom in the complexes is 4 D 1/2 . The fluorescent intensity and the lifetime of the supramolecular encapsulation products of (CH 3) 3Si-MCM-41 and Sm 3+ complexes are stronger and longer than those of the encapsulation products of MCM-41 and Sm 3+ complexes respectively. The results show that the host with lipophilic channels is more favourable to the fluorescence of the rare earth complexes than the hydrophilic mesoporous molecular sieve. The fluorescent intensity of (CH 3) 3Si-MCM-41-Sm(Phen) 3(TTA)(NO 3) 3 is the strongest \{among\} the encapsulation series of Sm 3+ complexes, which is assumed to result from the greatly reduction of SiO-H vibration relaxation in host (CH 3) 3Si-MCM-41 and the presence of the discrete strong luminescent centres of the guest molecules associated with the nanosized material′s structure. The luminescent decay halftime of the supramolecular materials is much shorter than that of the powder of the samarium complexes. The result shows that the ligand transferring energy from the triplet state to the singlet state of Sm 3+ ( T 1→S , intersystem crossing) becomes higher. The fluorescent experimental results indicate that the interaction between the host and the guest influences the luminescent properties of the nanostructured supramolecular materials.
