作者:Michael E. Mulholland、Daminda Navarathne、Samim Khedri、W. G. Skene
DOI:10.1039/c4nj00027g
日期:——
A series of conjugated azomethines end-capped with phenylamides and consisting of different aromatic cores of varying π-donor strength were prepared. Their optical and electrochemical properties were investigated to assess the suitability of the azomethines as electrochromic materials. The azomethines were found to undergo both electrochemical oxidation and reduction in the window of −1.60 and +1.35 V vs. Ag/Ag+. The color of the ambipolar compounds could be dramatically changed when switched between their reduced, neutral, and oxidized states. The color of the different states was contingent on the π-donor strength of the central aromatic unit. The largest spectral difference of 350 nm between the reduced and oxidized states was observed when the central aromatic group was 3,4-ethylenedioxythiophene (EDOT). The colors detectable by the eye for this EDOT derivative were blue, red, and bleached for the reduced, neutral, and oxidized states, respectively. The multichromatic azomethine was used as an electrochromic layer in a functioning device. The proof-of-concept ambipolar electrochromic device could be repeatedly switched between its orange (neutral) and purple (reduced) states. The device could also be switched to its oxidized (bleached) state.
制备了一系列以苯基酰胺封端的共轭偶氮甲烷,它们由具有不同π-供体强度的不同芳香族核组成。研究人员对其光学和电化学性质进行了研究,以评估偶氮甲烷作为电致变色材料的适用性。研究发现,偶氮甲烷在-1.60和+1.35 V vs. Ag/Ag+的范围内会发生电化学氧化和还原。当在还原、中和氧化状态之间切换时,双极化化合物的颜色会发生显著变化。不同状态的颜色取决于中心芳香基团的π-供体强度。当中心芳香基团为3,4-乙撑二氧噻吩(EDOT)时,还原和氧化状态之间的最大光谱差异为350 nm。对于这种EDOT衍生物,还原、中和氧化状态的颜色分别为蓝色、红色和漂白色,肉眼可识别。多色偶氮甲烷被用作功能性器件中的电致变色层。这种双极电致变色器件的概念验证可以在橙色(中性)和紫色(还原)状态之间反复切换。该器件还可以切换到氧化(漂白)状态。