Investigating the backbone conformation and configuration effects for donor-acceptor conjugated polymers with ladder-type structures synthesized through Aldol polycondensation
Journal
Journal of Materials Chemistry C
Journal Volume
9
Journal Issue
30
Pages
9473-9483
Date Issued
2021
Author(s)
Abstract
Aldol reaction is a green approach that is exclusively suitable for developing conjugated polymers (CPs) with ladder-type structures. Herein, electron-deficient non-fused and fused bis-isoindigo (bis-IID) are copolymerized with axisymmetric thiophene (T) or centrosymmetric thieno[3,2-b]thiophene (TT) electron-rich spacers through Aldol polycondensation to prepare four donor-acceptor (D-A) CPs with ladder-type structures. The non-fused (P1andP2) and fused (P3andP4) bis-IIDs on the backbone lead to varied conformational flexibility that dominates aggregation, energy levels, and packing of the polymers.P3andP4with a planar backbone exhibit a stronger aggregation and lower bandgap (1.38 eV) thanP1andP2(?1.8 eV), while their intense non-crystalline aggregation also results in an amorphous structure. Meanwhile, the configurational differences arising from axisymmetric T unit (P1andP3) and centrosymmetric TT unit (P2andP4) spacers is shown to deeply affect the surface morphology and film ductility. The non-planar backbone endowsP1andP3with low surface roughness and high brittleness. The combined low conformation and configuration regularity account for the inferior mobility ofP1. On the contrary,P2-P4exhibit comparable hole mobility ranging from 10?2-10?3cm2V?1s?1and up to 0.011 cm2V?1s?1(P2), due to their better regularity in both conformation and configuration. Collectively, our results provide a new perspective for designing new D-A CPs through Aldol polycondensation. ? The Royal Society of Chemistry 2021.
Subjects
Condensation reactions
Fracture mechanics
Hole mobility
Ketones
Ladders
Morphology
Polycondensation
Shims
Surface morphology
Surface roughness
Thiophene
Aldol reactions
Amorphous structures
Conformation and configuration
Conformational flexibility
Donor-acceptor conjugated polymers
Electron-deficient
Ladder-type structure
Low surface roughness
Conjugated polymers
SDGs
Type
journal article