181367-10-2Relevant academic research and scientific papers
Multistate near-infrared electrochromism and electron transfer in different oligotriphenylamine systems
Zhang, Jing,Liu, Guotao,Wang, Xiao-Yan,Yu, Guang-Ao,Yin, Jun,Liu, Sheng-Hua
, p. 416 - 426 (2017)
Four oligomeric triarylamine compounds (diamine 1a, triamine 1b, tetramine 1c and pentamine 1d) were prepared and characterized by 1H NMR, mass spectrometry and elemental analysis. The combined results of cyclic voltammetry, square-wave voltammetry and UV–vis–NIR spectroelectrochemistry, as well as density functional theory, reveal that compounds 1a–1d display two to five steps of oxidation processes, respectively, and the ΔE1/2 and Kc values were still remarkable for the relatively long pentamine, though they all decreased with an increase of the triphenylamine unit. These four compounds all exhibit fascinating redox-tuned multiple NIR absorption characteristics, and a completely reversible multicolor electrochromism for each of them could be synchronously realized. The associated mono-cationic [1a]+–[1d]+ could be classified as moderately-coupled Robin–Day class II mixed-valence systems, which could be stabilized by spin delocalization over at least two adjacent amine units.
Spectral and redox properties of zinc porphyrin core dendrimers with triarylamines as dendron
Huang, Chih-Yen,Su, Yuhlong Oliver
, p. 8306 - 8312 (2010)
The first and second generation of zinc porphyrin core dendrimers (3 and 4) with triarylamine as dendron have been synthesized via Ullmann coupling reaction. Their absorption and emission spectra indicate that there are strong interactions between zinc porphyrin core and triarylamine dendrons. Zinc porphyrin links with triarylamine causes Soret band broadening and Q band shift as compared with ZnTPP. Because of the antenna effect on these dendrimers, the fluorescence quantum yields were strongly enhanced when more triarylamine moieties were linked. Cyclic voltammetry and spectroelectrochemical methods were used to investigate the redox properties of dendrimers. Axial ligation of zinc porphyrin with N-methylimidazole is useful in differentiating the oxidation site of dendrimers. For the first generation dendrimer (3), porphyrin ring oxidation potential shifts cathodically because the periphery dendrons are strong electron-donating groups. On the other hand, the dendrons of the second generation (4) are oxidized first and generate an atmosphere of eight positive charges. The porphyrin ring core is then oxidized with an anodic shift in potential due to the electron-withdrawing effect of the oxidized substituents.
