Mizoshita Norihiro, Goto Yasutomo, Kapoor Mahendra P, Shimada Toyoshi, Tani Takao, Inagaki Shinji
Toyota Central R&D Laboratories, Inc. Nagakute, Aichi 480-1192, Japan.
Chemistry. 2009;15(1):219-26. doi: 10.1002/chem.200801238.
We report that 2,6-naphthylene-bridged periodic mesoporous organosilicas exhibit unique fluorescence behavior that reflects molecular-scale periodicities in the framework. Periodic mesoporous organosilicas consisting of naphthalene-silica hybrid frameworks were synthesized by hydrolysis and condensation of a naphthalene-derived organosilane precursor in the presence of a template surfactant. The morphologies and meso- and molecular-scale periodicities of the organosilica materials strongly depend on the synthetic conditions. The naphthalene moieties embedded within the molecularly ordered framework exhibited a monomer-band emission, whereas those embedded within the amorphous framework showed a broad emission attributed to an excimer band. These results suggest that the naphthalene moieties fixed within the crystal-like framework are isolated in spite of their densely packed structure, different from conventional organosilica frameworks in which only excimer emission was observed for both the crystal-like and amorphous frameworks at room temperature. This key finding suggests a potential to control interactions between organic groups and thus the optical properties of inorganic/organic hybrids.
我们报道，2,6-萘桥连的周期性介孔有机硅表现出独特的荧光行为，这种行为反映了骨架中的分子尺度周期性。通过在模板表面活性剂存在下，使萘衍生的有机硅烷前体水解和缩合，合成了由萘-二氧化硅杂化骨架组成的周期性介孔有机硅。有机硅材料的形态以及介观和分子尺度的周期性强烈依赖于合成条件。嵌入分子有序骨架内的萘部分表现出单体带发射，而嵌入无定形骨架内的萘部分则显示出归因于准分子带的宽发射。这些结果表明，固定在类晶体骨架内的萘部分尽管结构紧密堆积，但却是孤立的，这与传统的有机硅骨架不同，在传统有机硅骨架中，在室温下类晶体和无定形骨架均仅观察到准分子发射。这一关键发现表明了控制有机基团之间相互作用以及由此控制无机/有机杂化物光学性质的潜力。
