Asymmetric imidazole/pyrene/pyrazine based D-π-A compounds showing visualized acidichromism and near-infrared electrochromism

Two asymmetric imidazole/pyrene/pyrazine centered D-pi-A compounds (PyMB-1 and PyMB-2), bearing 4-[N,N-bis(4-methoxyphenyl)amino]phenyl/4-[N,N-bis[4-(di-4-anisylamino)phenyl]amino]Phenyl and didodecyloxybenzene terminals, have been synthesized and characterized in this work. It is found that the color of two compounds could change from light yellow to brown after the treatment with trifluoroacetic acid (TFA) in their CH2Cl2 solutions, which could be detected by direct visual observation. In addition, the thin film of 4-[N,N-bis[4-(di-4-anisylamino)phenyl]amino]phenyl terminated compound shows reversible electrochromic behavior accompanied by a color alteration from yellow to green under different bias voltages, which could be monitored by in situ UV-vis and near-infrared (NIR) spectroscopy. (C) 2015 Elsevier Ltd. All rights reserved.