It was proved by ICP, fluorescence spectra and N 2 adsorption that the rare earth complex [C 5H 5NC 16H 33] [Eu(TTA) 4] is in the channel of Si-MCM-41 in the course of assembly. The rare earth complex of 67.9% is in t...It was proved by ICP, fluorescence spectra and N 2 adsorption that the rare earth complex [C 5H 5NC 16H 33] [Eu(TTA) 4] is in the channel of Si-MCM-41 in the course of assembly. The rare earth complex of 67.9% is in the channel, suggesting that the assembly of the complex molecular on the mesoporous MCM-41 was carried out mainly in the channel.展开更多
Eu(TTA)4C5H5NC16H33(TTA:1-(2-Thenoy)-3,3,3-Trifluoracetate) is encapsulated in St- MCM-41 modified with N-(3-Trimethoxysilethyl)ethylene. The emission spectrum of the assembly shows only a 5D0-7F2 transition. As comp...Eu(TTA)4C5H5NC16H33(TTA:1-(2-Thenoy)-3,3,3-Trifluoracetate) is encapsulated in St- MCM-41 modified with N-(3-Trimethoxysilethyl)ethylene. The emission spectrum of the assembly shows only a 5D0-7F2 transition. As compared with the rare earth complex itself, the lifetime of the assembly becomes longer and its stability under the UV radiation is much better.展开更多
Well-defined Si- and Ti-MCM-41 mesoporous molecular sieves were synthesized in high yields through the halogen anion mediated S(+)X(-)I(+) assembly in the presence of cetylpyridinium bromide as template. The spectrosc...Well-defined Si- and Ti-MCM-41 mesoporous molecular sieves were synthesized in high yields through the halogen anion mediated S(+)X(-)I(+) assembly in the presence of cetylpyridinium bromide as template. The spectroscopy characterization of the as-synthesized samples confirmed that Ti (IV) could be isolated in the lattice positions of the MCM-41 mesostructure by this method.展开更多
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
Among rare earth complexes Tb(Phen)_ x (Bipy)_((4- x ))(NO_3)_3 ( x =4,3,2,1,0) solutions (1×10 (-3) (mol·L (-1)),) the fluorescent intensity of Tb (3+) in Tb(Phen)_3(Bipy)(NO_3)_3 is strongest and that of T...Among rare earth complexes Tb(Phen)_ x (Bipy)_((4- x ))(NO_3)_3 ( x =4,3,2,1,0) solutions (1×10 (-3) (mol·L (-1)),) the fluorescent intensity of Tb (3+) in Tb(Phen)_3(Bipy)(NO_3)_3 is strongest and that of Tb (3+) in Tb(Bipy)_4(NO_3)_3 is weakest. The fluorescent intensity of Tb (3+) in (CH_3)_3Si-MCM-41-Tb(Bipy)_4(NO_3)_3 is strongest and that of Tb (3+) in MCM-41-Tb(Phen)_3(Bipy)(NO_3)_3 or (CH_3)_3Si-MCM-41-Tb(Phen)_3(Bipy)(NO_3)_3 becomes very weak. Luminescence supramolecular nanostructured materials that the guests Tb(Phen)_4(NO_3)_3 and Tb(Bipy)_4(NO_3)_3 were encapsulated in the non-polar channels of (CH_3)_3Si-MCM-41 are stronger than that encapsulated in the polar channels of MCM-41. When the guests are Tb(Phen)_3(Bipy)(NO_3)_3 and Tb(Phen)_2(Bipy)_2(NO_3)_3,the result is just opposite. The results were proved by fluorescent lifetime experiments. MCM-41-Tb(Phen)(Bipy)_3(NO_3)_3 shows two distinct exponential decays,which time constants are 168.8 and 641.1 μs and its amplitude ratio is 0.96∶1. The same as (CH_3)_3Si-MCM-41-Tb(Phen)(Bipy)_3(NO_3)_3 shows,of which are 73.2 and 590.4 μs and the amplitude ratio is 2.3∶1. The ratios of decay time and luminescence intensity of the both supramolecular systems are 2.5∶1,1∶2.5 and 1.1∶1,0.96∶1,respectively. These results indicate that interaction and selectivity between host and guest influence greatly luminescent properties of supramolecular system.展开更多
文摘It was proved by ICP, fluorescence spectra and N 2 adsorption that the rare earth complex [C 5H 5NC 16H 33] [Eu(TTA) 4] is in the channel of Si-MCM-41 in the course of assembly. The rare earth complex of 67.9% is in the channel, suggesting that the assembly of the complex molecular on the mesoporous MCM-41 was carried out mainly in the channel.
文摘Eu(TTA)4C5H5NC16H33(TTA:1-(2-Thenoy)-3,3,3-Trifluoracetate) is encapsulated in St- MCM-41 modified with N-(3-Trimethoxysilethyl)ethylene. The emission spectrum of the assembly shows only a 5D0-7F2 transition. As compared with the rare earth complex itself, the lifetime of the assembly becomes longer and its stability under the UV radiation is much better.
文摘Well-defined Si- and Ti-MCM-41 mesoporous molecular sieves were synthesized in high yields through the halogen anion mediated S(+)X(-)I(+) assembly in the presence of cetylpyridinium bromide as template. The spectroscopy characterization of the as-synthesized samples confirmed that Ti (IV) could be isolated in the lattice positions of the MCM-41 mesostructure by this method.
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.
文摘Among rare earth complexes Tb(Phen)_ x (Bipy)_((4- x ))(NO_3)_3 ( x =4,3,2,1,0) solutions (1×10 (-3) (mol·L (-1)),) the fluorescent intensity of Tb (3+) in Tb(Phen)_3(Bipy)(NO_3)_3 is strongest and that of Tb (3+) in Tb(Bipy)_4(NO_3)_3 is weakest. The fluorescent intensity of Tb (3+) in (CH_3)_3Si-MCM-41-Tb(Bipy)_4(NO_3)_3 is strongest and that of Tb (3+) in MCM-41-Tb(Phen)_3(Bipy)(NO_3)_3 or (CH_3)_3Si-MCM-41-Tb(Phen)_3(Bipy)(NO_3)_3 becomes very weak. Luminescence supramolecular nanostructured materials that the guests Tb(Phen)_4(NO_3)_3 and Tb(Bipy)_4(NO_3)_3 were encapsulated in the non-polar channels of (CH_3)_3Si-MCM-41 are stronger than that encapsulated in the polar channels of MCM-41. When the guests are Tb(Phen)_3(Bipy)(NO_3)_3 and Tb(Phen)_2(Bipy)_2(NO_3)_3,the result is just opposite. The results were proved by fluorescent lifetime experiments. MCM-41-Tb(Phen)(Bipy)_3(NO_3)_3 shows two distinct exponential decays,which time constants are 168.8 and 641.1 μs and its amplitude ratio is 0.96∶1. The same as (CH_3)_3Si-MCM-41-Tb(Phen)(Bipy)_3(NO_3)_3 shows,of which are 73.2 and 590.4 μs and the amplitude ratio is 2.3∶1. The ratios of decay time and luminescence intensity of the both supramolecular systems are 2.5∶1,1∶2.5 and 1.1∶1,0.96∶1,respectively. These results indicate that interaction and selectivity between host and guest influence greatly luminescent properties of supramolecular system.
