Exploration of Syntheses and Functions of Higher Ladder-type π-Conjugated Heteroacenes

Abstract

Ladder-type heteroacenes with well-defined structures and highly planar and delocalized p-electrons are an important class of materials for potential applications in organic electronics. The incorporation of heteroatoms into the ladder backbone allows for tuning optical-electronic properties and crystal structures in the solid state. Significant progress in synthesis and physical studies of a number of fascinating ladder molecules has been achieved. This review discusses progression in synthetic methods, structural characterization, and applications of ladder-type heteroacenes.

Foldable semi-ladder polymers: novel aggregation behavior and high-performance solution-processed organic light-emitting transistors

“…The semi-ladder polymers were synthesized via Suzuki coupling polymerization of electron-accepting monomer 5,11-bis(2butyloctyl)-dihydrothieno[2 0 ,3 0 :4,5]pyrido[2,3-g]thieno[3,2-c] quinoline-4,10-dione (TPTQ) or TPTQF dibromide with electron-donating chromophore carbazole (C) monomer containing bis(pinacolato)di-boron (BPin) moieties. [25][26][27][28][29] The resulting polymers are cross-conjugated and exhibit excellent uorescent properties (Fig. 1a).…”

Extraordinary electrochemical stability and extended polaron delocalization of ladder-type polyaniline-analogous polymers

“…The covalently locked coplanar conformation of a conjugated ladder-type backbone, 1 in contrast with conventional non-ladder polymers with torsional rotation, allows for extensive intrachain delocalization of molecular orbitals and transport of quasi-particles such as charges, excitons, polarons, and spins. [2][3][4] The rigid coplanar conformation can also enhance interchain electronic coupling of conjugated ladder polymers due to the small reorganization energy of a rigid system upon electron transfer or photoexcitation, [5][6][7][8] which is important for solid-state materials properties. In addition, a signicantly higher activation energy is required to break the double-stranded backbones of a ladder polymer, translating to high stability that is important for applications under harsh conditions.…”

One‐Step Route to Ladder‐Type C–N Linked Conjugated Polymers

“…Ladder‐type conjugated polymers are a specific subtype of ladder polymers in which all the fused rings in the backbone are pi‐conjugated, which have raised considerable interest because of their unique structures and attractive properties . Many attempts have been made to explore novel approaches for synthesizing new class of ladder‐type conjugated polymers .…”