Electrochromic polyiminocarbazolylenes with latent hydrogen bonding

摘要: Polyiminoarylenes with carbazole (cbz) units in the main chain, or and side chain thermally cleavable t-butyloxycarbonyl (boc) groups were prepared upon palladium-catalyzed coupling reactions. Polymers from 2,7-dibromo-9-(2-ethylhexyl)-carbazole M1 9-(4-aminophenyl)carbazole hydrochloride M3 (P1-EH), 2,7-dibromo-9-t-butyloxycarbonyl-carbazole M2 (P1-BOC), 4-t-butylaniline M4 (P2-EH), (P2-BOC). Thermal treatment of boc-substituted polymers P1-BOC P2-BOC at 180 °C for ≥4 h led to removal boc formation insoluble P1-H P2-H strong adhesion substrate due hydrogen bonding (‘latent bonding’). For rate constant k deprotection could be determined about 0.050 min−1. Size exclusion chromatography indicated that molecular weights between 14 100 28 100 g mol−1. P1-EH, P1-BOC, P2-EH readily soluble toluene, THF, dichloromethane, chloroform, benzene, acetone methanol. After resulting polymer films common organic solvents. Optical electrochemical properties investigated. Due electron-rich nitrogen atoms can easily oxidized. Oxidation starts 0.31 V vs. SCE cation radicals. Further oxidation occurs 0.55 dications, 0.71 cbz units. At 1 are The electrochromic exhibit color changes colorless via orange green blue. Cbz potentials ≥0.71 leads dimers a reaction. cleavage well-adhering N–H-groups chains, ITO-substrate. best performance regard reversible was found P1-H. this electrochromism found. A contrast ratio 12% 900 nm, switching time 400 ms determined.