Cross-Linkable Fluorene-Diphenylamine Derivatives for Electrochromic Applications

• DOI: 10.1021/acsami.5b08218
• Publication Date: 2015-10-23T15:21:55Z
• Authors: Silja Abraham; Gayathri Prabhu T...; Sunil Varughese; Biswapriya Deb; Joshy Joseph
• Keywords: Electrochromic devices; Diphenylamine

Multicolor electrochromic systems based on heat cross-linkable arylamine-substituted fluorene derivatives, FD and FDOMe, are reported. These derivatives with pendant vinyl groups have been synthesized by the Buchwald-Hartwig amination reaction were well-characterized using various analytical spectroscopic techniques such as NMR, ESI-MS, single-crystal X-ray diffraction analysis. FDOMe exhibited thermally activated cross-linking above their melting temperatures, which was confirmed through absorption, differential scanning calorimetry (DSC), FT-IR, wide-angle (WAXD) techniques. Cross-linked films (FD-X) ITO showed two reversible redox peaks at 0.74 0.91 V (versus Ag/AgCl) that correspond to formation of radical cations dications, respectively. The corresponding observed 0.6 0.8 for cross-linked (FDOMe-X). Spectroelectrochemical studies revealed multicolor electrochromism FD-X (colorless-yellow-dark cyan) FDOMe-X (colorless-brick red-blue) a color contrast ∼44% 485 nm ∼63% 500 good switching stability between neutral oxidized states (>300 cycles) low voltages (<0.9 first oxidation <1.3 second oxidation). Furthermore, fabrication devices FTO substrate PMMA-based solid electrolyte demonstrated, where reasonably time (<30 s) optical contrast.