Functionalized [2.2]Paracyclophanedienes as Monomers for Poly(p-phenylenevinylene)s

Area of Science:

• Polymer Chemistry
• Organic Synthesis
• Materials Science

Background:

• Traditional synthesis of poly(p-phenylenevinylene)s (PPVs) lacks control over molecular weight, dispersity, and end groups.
• The monomer [2.2]paracyclophane-1,9-diene (pCpd) offers living polymerization but has limited structural diversity due to harsh synthesis conditions.

Purpose of the Study:

• To develop a general method for synthesizing diverse functionalized pCpds.
• To achieve living polymerization of functionalized PPVs with precise control over polymer architecture.
• To demonstrate the versatility of the synthesized PPVs through post-polymerization modification.

Main Methods:

• Synthesis of monohydroxy-pCpd via mono-demethylation of dialkoxy-pCpd.
• Functionalization of monohydroxy-pCpd with various side-chains (alkyl bromide, oligo(ethylene glycol), chiral moiety, protected amine).
• Living ring-opening metathesis polymerization (ROMP) of functionalized pCpds.
• Post-polymerization modification using azide-alkyne click chemistry.

Main Results:

• A general method for preparing functionalized pCpd monomers was established.
• Living ROMP yielded functionalized PPVs with controlled molecular weights, dispersities, and end groups.
• Post-polymerization modification via click chemistry successfully incorporated desired moieties.
• All synthesized PPVs exhibited solubility and consistent fluorescent emission, indicating intact conjugated backbones.

Conclusions:

• The developed method enables the synthesis of highly controlled, functionalized PPVs.
• This approach overcomes limitations of traditional PPV synthesis, offering precise control over polymer structure.
• The synthesized PPVs are versatile platforms for advanced materials development through controlled functionalization and modification.