Multistate near-infrared electrochromism and electron transfer in different oligotriphenylamine systems

Four oligomeric triarylamine compounds were prepared. 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. All the associated mono-cations 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.334