吡啶基咪唑[4,5-f]1,10-菲咯啉的合成、表征及与瓜环作用的光谱学考察

Synthesis,Characterization of Pyridylimidazo [4,5-f]1,10-phenanthroline Derivates and Their Spectroscopic Study after Interacted with Cucurbit [n] urils

设计合成了2个吡啶基菲咯啉衍生物2-(3-吡啶基)咪唑[4,5-f]1,10-菲咯啉(G1)和2-(4-吡啶基)咪唑[4,5-f]1,10-菲咯啉(G2),通过元素分析、质谱和核磁共振氢谱对其结构进行了表征。利用紫外吸收光谱和荧光光谱法考察了所合成化合物与六元瓜环Q[6]、七元瓜环Q[7]的相互作用,以及体系pH值对主-客体相互作用的影响。在酸性条件下,Q[6]、Q[7]与Gl以及Q[6]与G2均发生包合形成1∶1的包合物,并有荧光增敏作用;Q[7]与G2作用形成1∶2包合物,且对G2有荧光猝灭作用;Q[6]、Q[7]与G1的包合常数分别为3.00×104和1.86×104 L/mol;Q[6]、Q[7]与G2的包合常数分别为1.64×104和1.01×103 L/mol。随着体系酸性减弱,瓜环与客体作用减弱,在中性条件下,瓜环未与客体发生包合作用。

Two pyridyl imidazo[4,5-f]1,10-phenanthroline derivates,namely 2-（3-pyridyl）-imidazo[4,5-f]1,10-phenanthroline（G1） and 2-（4-pyridyl）imidazo [4,5-f]1,10-phenanthroline（G2）,were synthesized and characterized by elemental analysis,1H NMR and MS.Under various concentrations of cucurbit[n]urils（Q[n],n=6,7）,the interaction of Q[n] with G1 and G2 were studied in buffer solutions with different pH values by using UV-Vis spectroscopy and fluorescence spectrophotometry.The results revealed that cucurbit[n]urils（n=6,7） form a 1∶ 1 complex with G1,and Q[6] form a 1∶ 1 complex with G2 in acidic solution,fluorescent sensitizing effects of both Q[6] and Q[7] toward guests were determined.Under acidic solution Q[7] formed a 2∶ 1 complex with G2,and a fluorescent quenching effect of Q[7] on G2 was observed.Association constants（K） of Q[n]（n=6,7） with G1 were found to be 3.00×104 L/mol,1.86×104 L/mol respectively,while those of Q[n]（n=6,7） with G2 are 1.64×104 L/mol and 1.01×103 L/mol respectively.With decreasing acidity of the systems,the interaction between guests and Q[n]（n=6,7） weakened and no interaction was observed under neutral conditions.