Synthesis and properties of 2,6-azulene-based conjugated polymers and their applications in dispersing single-walled carbon nanotubes

Abstract

Azulene-based conjugated polymers exhibit unique features that can be exploited in several applications, including energy storage, coatings, sensors and printed electronics. The position by which the azulene is linked to its comonomers plays a major role in the properties of the resulting polymers. Herein, we describe the synthesis and characterization of a new series of 2,6-azulene-based conjugated polymers, a scarcely studied class of conjugated polymers. We took advantage of the facilitated electron delocalization along the C₂ axis by designing a bisborylated azulene moiety that allowed the preparation of a series of copolymers using dibrominated π-conjugated units. These polymers absorb light in the visible region in the neutral form and up to the near infrared upon protonation. These polymers were used to efficiently disperse single walled carbon nanotubes (SWNTs) to yield nanocomposites with conductivity values of up to 6 S cm⁻¹.