Structure resembling effect of clay surface on photochemical properties of meso-phenyl or pyridyl-substituted monocationic antimony(V) porphyrin derivatives
Structure resembling effect of clay surface on photochemical properties of meso-phenyl or pyridyl-substituted monocationic antimony(V) porphyrin derivatives
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DOI：
10.1039/c4ra15650a
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发表时间：
2015-01
期刊：
影响因子：
3.9
通讯作者：
T. Tsukamoto;T. Shimada;S. Takagi
中科院分区：
文献类型：
--
作者：
T. Tsukamoto;T. Shimada;S. Takagi
合成了四种不同疏水性的中位苯基或吡啶取代的单阳离子锑(V)卟啉衍生物(SbVPors)--5，10，15，20-四苯基；5，10，15-三苯基-20-单(4-吡啶)；5，15-二苯基-10，20-二(4-吡啶)；以及5，10，15，20-四(4-吡啶基)二羟基锑(V)氯化物，并研究了它们在阴离子粘土上的光化学性质。SbVPors的吸收和荧光行为受到与粘土形成络合物的强烈影响。有趣的是，SbVPors在粘土表面的吸收跃迁几率和荧光量子产率显著增加。SbVPor的疏水性越强，其吸收跃迁几率增加越多，荧光量子产率增加越多。利用SbVPor的势能曲线，主要从跃迁几率的角度讨论了粘土表面高度平坦对SbVPor光化学行为的影响。对于疏水性较强的SbVPor，由于卟啉与粘土表面具有较强的疏水相互作用，即“结构相似效应”，使得粘土表面基态和激发态的分子结构趋于相似。这一效应导致了跃迁概率的变化。
Four types of meso-phenyl or pyridyl-substituted monocationic antimony(V) porphyrin derivatives (SbVPors)—5,10,15,20-tetraphenyl; 5,10,15-triphenyl-20-mono(4-pyridyl); 5,15-diphenyl-10,20-di(4-pyridyl); and 5,10,15,20-tetra(4-pyridyl)porphyrinato dihydroxo antimony(V) chloride—with different hydrophobicities were synthesised, and their photochemical properties on anionic clay were investigated. The absorption and fluorescence behaviour of the SbVPors were strongly affected by complex formation with clay. Interestingly, the absorption transition probabilities and fluorescence quantum yields of the SbVPors prominently increased on the clay surface. The more hydrophobic SbVPor showed greater absorption transition probability increase and fluorescence quantum yield enhancement. These unique effects of the highly flat clay surface on the photochemical behaviour of SbVPor were discussed mainly from the viewpoint of transition probability, by using the potential energy curves of SbVPor with and without clay. For the more hydrophobic SbVPor, the molecular structure of the ground and excited states on the clay surface tended to become similar because of the strong hydrophobic interaction between porphyrin and the clay surface, i.e. the ‘structure resembling effect’. This effect induces a change in the transition probabilities.