We present the absorption and fluorescence spectra of (E)-N-(4-(dimethylamino)benzylidene)-2H-1,2,4-triazol-3-amine (DMABA-Amtr), an electron donor-π-acceptor system. The molecule shows a single fluorescence emission band in non-polar solvents while dual emissions were observed in polar aprotic solvents. Although several researchers over the years provide different explanations for the mechanism of the phenomena, based on solvent assisted excited state geometry changes of such systems, it is still a matter of controversy since such systems are unique as they contradict Kasha's rule. The emission spectrum of the molecule shows strong dependence on solvent polarity and excitation wavelength. This observation together with a single iso-emissive point found in the area normalize emission spectra indicates the presence of two ground state equilibrium structures of the compound which are both fluorescent. Density functional theory (DFT) and time-dependent (TD-DFT) calculations also support the experimental findings.

我们展示了（E的吸收和荧光光谱）-N-（4-（二甲基氨基）亚苄基）-2H-1,2,4-三唑-3-胺（DMABA-Amtr），一个电子供体-π-受体系统。该分子在非极性溶剂中显示单个荧光发射带，而在极性非质子溶剂中观察到双发射。尽管多年来研究人员针对这种现象的机理提供了不同的解释，但基于此类系统的溶剂辅助激发态几何变化，这仍然是一个有争议的问题，因为此类系统与Kasha规则相矛盾，因此具有独特性。分子的发射光谱显示出对溶剂极性和激发波长的强烈依赖性。该观察结果与在该区域归一化发射光谱中发现的单个等发射点一起表明该化合物存在两个均是荧光的基态平衡结构。