Pure Blue-Light-Emitting Materials: Hyperbranched Ladder-Type Poly(<i>p</i>-phenylene)s Containing Truxene Units

Abstract

A series of novel hyperbranched ladder-type poly(p-phenylene)s containing truxene units have been prepared through the Pd(0)-catalyzed Suzuki polymerization with an “A2 + B3” or “A2 + B2+ B3” approach. The polymers with different linear length show pure blue light emission from 417 to 465 nm. All the ladder-type polymers exhibit well-resolved absorption and emission spectra and small Stokes shifts in both solutions and thin films, which are the characteristics of full ladder-type poly(p-phenylene)s. The three-dimensional structures make the materials soluble in common organic solvents and able to form quality amorphous films, leading to polymer light-emitting diodes (PLEDs) with improved stability and efficiency.