Functional silicon crosslinks in conjugated polymer networks

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Amorphous conjugated polymer networks (CPNs) are advanced materials with tunable electronic properties.
• Incorporating main group elements, especially Group 14 (Si, Ge, Sn), into CPNs offers new functionalities but is synthetically challenging.
• Existing research on CPNs primarily focuses on heteroatoms (N, O, S), with limited exploration of Group 14 elements due to a lack of suitable crosslinkers.

Purpose of the Study:

• To develop a novel crosslinker for synthesizing amorphous CPNs containing Group 14 elements.
• To create and characterize silicon-silicon (Si-Si) crosslinked π-conjugated polysilafluorenes.
• To investigate the electronic structure and redox activity of these novel materials.

Main Methods:

• Synthesis of a novel disilane-containing crosslinker.
• Preparation of Si-Si crosslinked π-conjugated polysilafluorenes.
• Characterization using 1H, 13C, and 29Si NMR spectroscopy.
• Computational modeling using density functional theory (DFT) on oligomer models.

Main Results:

• Successful synthesis of novel Si-Si crosslinked π-conjugated polysilafluorenes with tunable crosslinking.
• Rigorous structural and electronic characterization confirming the presence of Si-Si crosslinks.
• DFT calculations indicated decreased Si-Si bond dissociation energies upon reduction or oxidation, suggesting redox activity.
• Demonstrated a new synthetic strategy utilizing Si-Si bonds as crosslinks in macromolecules.

Conclusions:

• A novel disilane crosslinker enables the synthesis of Si-Si crosslinked conjugated polymer networks.
• These materials exhibit tunable crosslinking and redox-active properties, opening new avenues in materials science.
• This work addresses the synthetic limitations in preparing Group 14-containing CPNs and introduces a new class of silicon-based polymers.