Luminescence of Nanosized Supramolecular Material of Mesoporous Molecular Sieve and Terbium Complex

Among rare earth complexes Tb（Phen） x （Bipy）（4- x ）（NO3）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）（NO3）3 is strongest and that of Tb （3+） in Tb（Bipy）4（NO3）3 is weakest. The fluorescent intensity of Tb （3+） in （CH3）3Si-MCM-41-Tb（Bipy）4（NO3）3 is strongest and that of Tb （3+） in MCM-41-Tb（Phen）3（Bipy）（NO3）3 or （CH3）3Si-MCM-41-Tb（Phen）3（Bipy）（NO3）3 becomes very weak. Luminescence supramolecular nanostructured materials that the guests Tb（Phen）4（NO3）3 and Tb（Bipy）4（NO3）3 were encapsulated in the non-polar channels of （CH3）3Si-MCM-41 are stronger than that encapsulated in the polar channels of MCM-41. When the guests are Tb（Phen）3（Bipy）（NO3）3 and Tb（Phen）2（Bipy）2（NO3）3,the result is just opposite. The results were proved by fluorescent lifetime experiments. MCM-41-Tb（Phen）（Bipy）3（NO3）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 （CH3）3Si-MCM-41-Tb（Phen）（Bipy）3（NO3）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.