Polymerization of monolayers of 3-substituted pyrroles

Derivatives of 3-substituted pyrroles were spread at the air-water interface. Stable films could be obtained for pyrroles with side chains containing more than 10 carbons. 3-Hexadecanoylpyrrole could not be polymerized as a monolayer whereas the alkyl derivatives could be polymerized successfully without having additional monomer in the subphase. The monolayers could be transferred onto hydrophobic substrates with transfer ratios close to unity. The polymers formed were soluble in chloroform and tetrahydrofuran. Molecular-weight averages obtained by gel permeation chromatography ranged from 3500 to 6000 when polymerized on ammonium peroxydisulfate and 5000 to 15000 when polymerized on ferric chloride subphase solutions. H-1 NMR indicates that the polymerization is highly regular, leading to a constitutionally ordered 2,5-poly(3-alkylpyrrole).