氧化蒽基二吲哚基甲烷显色现象的研究

通过两步反应合成了两个具有显色特性的化合物:氧化2-蒽基二吲哚基甲烷(2-AnBIM)和氧化9-蒽基二吲哚基甲烷(9-AnBIM).比较了它们在不同非质子溶剂、不同阴离子和酸性环境中的光谱行为.在非质子溶剂中,发现这两种化合物仅在CCl₄中有很大的红移,该红移现象的本质尚不清楚.浓度效应与NMR证据均表明在CCl₄中化合物存在基于氢键的分子间相互作用.在含有不同阴离子的乙腈中,2-AnBIM对F^-离子有选择性响应,而9-AnBIM则对F^-、Cl^-和Ac^-等阴离子均有响应;在质子性溶剂中二者均只对HSO₄^-有选择性响应.2-AnBIM与9-AnBIM在77 K下有荧光发射,而平面性较好的2-AnBIM具有较低的发射能级与较强的发光效率.室温下二者均无明显的荧光发射,这可能与激发态下快速的质子转移导致分子共轭、共平面程度降低有关.

Study on the Chromogenic Behaviors of Oxided Anthracyl Bis(indolyl)methane

Two chromogenic compounds,oxided 2-anthracyl bis(indolyl)methane(2-AnBIM) and oxided 9-anthracyl bis(indolyl)methane(9-AnBIM) were synthesized via two steps.The medium factors(polarity,anions and pH) on the absorption behaviors of the two compounds were studied.The difference of UV behaviors in other aprotic solvents is that both 2-AnBIM and 9-AnBIM show strong red shift in CCl4.Concentration effect and NMR data show aggregation of titled compounds could be formed at concentration of 1.0×10-5 mol/L in CCl4.In CH3CN,2-AnBIM acts as a selective colorimetric sensor only for F-,and 9-AnBIM could be sensitive for F-,Cl-and Ac-.Both compounds are sensitive only for HSO4-in CH3CN/H2O(4/1) system.Both 2-AnBIM and 9-AnBIM show fluorescence emission of intermolecular charge transfer(ITC) state at 77 K.More planarity of 2-AnBIM gives longer wavelength emission and higher quantum yield compared with 9-AnBIM.No obvious emission from 2-AnBIM and 9-AnBIM at room temperature are found,the reason might be from the fast proton transfer at excited state,which decreases the conjugation degree and co-plane of molecules.