Side‐chain induced chirality in diketopyrrolopyrrole based polymers

Abstract

Chiral all‐π‐conjugated conducting polymers are of significant importance because of their promising aspects ranging from organic electronics, organic spin filters, efficient water splitting materials, magneto‐optic materials to circularly polarized light emitters. Here, we report the synthesis and characterization of the first series of diketopyrrolopyrrole based chiral low band‐gap alternating copolymers. Alongside characterizations by UV and CD spectroscopy, AFM and FESEM were further performed to understand the morphology of the optically active polymers. The stereochemistry of the side‐chains on TDPP unit played a pivotal role in determining chiroptical properties and supramolecular self‐assembly of the copolymers in solution which lead to layer‐by‐layer helical morphology in solid‐state. Interestingly, D‐A intramolecular charge transfer transition showed Cotton effect with bimodal nature, which is remarkably stronger than the π‐π* transition.

Self‐assembly of chiral diketopyrrolopyrrole chromophores giving supramolecular chains in monolayers and twisted microtapes

“…Alternative functionalization along the aryl backbone through the Knoevenagel condensation reaction with amide and semicarbazone motifs has been described for ThDPP ‐based systems 55–58 . With regard to chirality, alkyl, amide, and amino acid side chains have been typically introduced through N‐ alkylation at the lactam 59–64 . Additionally, end capping of the aryl system to give axially chiral systems with promising circularly polarized luminescence (CPL) properties has been detailed 65–68 .…”

“… 55 , 56 , 57 , 58 With regard to chirality, alkyl, amide, and amino acid side chains have been typically introduced through N‐ alkylation at the lactam. 59 , 60 , 61 , 62 , 63 , 64 Additionally, end capping of the aryl system to give axially chiral systems with promising circularly polarized luminescence (CPL) properties has been detailed. 65 , 66 , 67 , 68 Imparting said motifs that promote self‐assembly on to the DPP skeleton has seen systems that form gels, 62 , 69 , 70 nanowires, 71 and liquid crystals 72 , 73 among others.…”

Identification of Supramolecular Structures of Porphyrin Polymer on Single-Walled Carbon Nanotube Surface Using Microscopic Imaging Techniques

“…Porphyrins, related compounds, and other polymers become significant candidates in many potential applications (i.e., electronic devices, physics, and many materials science applications) [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] as they have remarkable physical and chemical features, in addition, they can be simply synthesized with a wide substituent range.…”

Chiral Diketopyrrolopyrrole-Based Conjugated Polymers with Intramolecular Rotation–Isomeric Conformation Asymmetry for Near-Infrared Circularly Polarized Light-Sensing Organic Phototransistors

“…In this regard, various π-conjugated polymers with a chiral pendant alkyl side chain attached to the representative conjugated backbone, such as polyfluorene, poly­( p -phenylene ethynylene), polythiophene, or poly­(fluorene- alt -phenyl), have been explored. − These chiral-side-chain polymer thin films exhibit interchain aggregates and form chiral nematic (e.g., cholesteric) supramolecular assemblies through the self-organized compact packing of an achiral π-skeleton. As a result, they demonstrate significant chiroptical activity through exciton coupling between adjacent polymer chains in the solid state. − However, their application for NIR CP light detection has been limited due to the large optical band gap of the polymer, restricting device operation to the visible-light spectrum.…”