Near-Infinite-Chain Polymers with Ge=Ge Double Bonds

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Chemistry

Background:

• Conjugated polymers with heavier p-block elements are scarce.
• Previous synthesis of Ge=Ge polymers yielded insoluble materials with low polymerization degrees.

Purpose of the Study:

• To synthesize soluble conjugated polymers incorporating germanium-germanium double bonds.
• To investigate the conjugation, assembly, and structural properties of these novel polymers.

Main Methods:

• Heavier acyclic diene metathesis (HADMET) polymerization with long alkyl chains.
• Diffusion-ordered NMR spectroscopy (DOSY) and dynamic light scattering (DLS) for polymerization degree.
• UV/Vis and NMR spectroscopy for conjugation analysis.
• X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) for structural characterization.

Main Results:

• Achieved soluble polymers with exceptionally high degrees of polymerization.
• Confirmed σ,π-conjugation through silylene-phenylene linkers and Ge=Ge bonds.
• Observed formation of ladder-like cylindrical assemblies driven by intermolecular dispersion interactions.
• Thin films showed lamellar ordering of polymer bundles.

Conclusions:

• Successfully synthesized soluble, high molecular weight conjugated polymers containing Ge=Ge bonds.
• Demonstrated the potential for creating ordered supramolecular structures from these polymers.
• Opened new avenues for exploring heavier p-block elements in conjugated polymer design.