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Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Self-assembly of dendronized perylene bisimides into complex helical columns
Virgil Percec1, Mihai Peterca, Timur Tadjiev
1Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA. percec@sas.upenn.edu
Journal of the American Chemical Society
|June 25, 2011
Summary
Dendronized perylene bisimides self-assemble into ordered columnar phases. The molecular arrangement, whether tetrameric or helical, depends on the linker length, influencing their potential in organic electronics.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Organic Electronics
Background:
- Perylene 3,4:9,10-tetracarboxylic acid bisimides (PBIs) are crucial organic semiconductors.
- Dendronization offers a route to control PBI self-assembly and material properties.
- Understanding structure-property relationships is key for advanced applications.
Purpose of the Study:
- To synthesize and characterize a series of first-generation dendronized PBIs.
- To investigate the effect of methylenic unit length (m) on self-assembly behavior.
- To explore the potential of these materials in organic electronics.
Main Methods:
- Synthesis of (3,4,5)12G1-m-PBI with varying 'm' values.
- Structural analysis using Differential Scanning Calorimetry (DSC) and X-ray diffraction.
- Solid-state (1)H NMR and molecular modeling on oriented samples.
Main Results:
- High-temperature self-assembly yields 2D-hexagonal columnar phases.
- Low-temperature self-assembly forms 3D columnar arrays: orthorhombic (m=0,2,3,4) and monoclinic (m=1).
- Orthorhombic phases feature tetrameric units with varied molecular orientations; monoclinic phase shows a helical repeat with aligned molecules.
Conclusions:
- The length of the methylenic linker significantly dictates the columnar self-assembly structure.
- The monoclinic helical structure (m=1) promotes enhanced π-stacking compared to other phases.
- These findings are relevant for designing dendronized PBIs for organic electronics and solar cells.
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