Department of Agriculture, University of Napoli Federico II, 80055 Portici NA, Italy.
Department of Chemical Sciences, University of Napoli Federico II, 80126 Napoli, Italy.
Molecules. 2020 Mar 17;25(6):1368. doi: 10.3390/molecules25061368.
Two novel symmetrical bis-azobenzene red dyes ending with electron-withdrawing or donor groups were synthesized. Both chromophores display good solubility, excellent chemical, and thermal stability. The two dyes are fluorescent in solution and in the solid-state. The spectroscopic properties of the neat crystalline solids were compared with those of doped blends of different amorphous matrixes. Blends of non-conductive and of emissive and conductive host polymers were formed to evaluate the potential of the azo dyes as pigments and as fluorophores. Both in absorbance and emission, the doped thin layers have CIE coordinates in the spectral region from yellow to red. The fluorescence quantum yield measured for the brightest emissive blend reaches 57%, a remarkable performance for a steadily fluorescent azo dye. A DFT approach was employed to examine the frontier orbitals of the two dyes.
合成了两种新型对称双偶氮苯红光染料，末端带有吸电子或供电子基团。两个生色团都具有良好的溶解性、优异的化学和热稳定性。两种染料在溶液中和固态中均具有荧光性。比较了纯晶态固体的光谱性质与不同无定形基质掺杂混合物的光谱性质。形成了非导电和发射性及导电性主体聚合物的混合物，以评估偶氮染料作为颜料和荧光团的潜力。掺杂的薄膜在吸收和发射方面在从黄色到红色的光谱区域都具有 CIE 坐标。对于最亮的发射性混合物，测量的荧光量子产率达到 57%，对于稳定荧光偶氮染料来说，这是一个显著的性能。采用 DFT 方法研究了两种染料的前线轨道。
