Cationic Facially Amphiphilic Poly(phenylene ethynylene)s Studied at the Air−Water Interface

The design of secondary conformation and chemically rich polymers that mimic natural biopolymers in function and structure is an important goal. Polymers based on meta -phenylene ethynylenes were patterned with polar, cationic, and nonpolar alkyl groups along the backbone with a repeat similar to amphiphilic β-sheet peptides. These polymers were characterized at the air−water interface by Langmuir techniques and found to adopt an edge-on, amphiphilic, extended conformation with an area per repeat unit of ∼42 Å. They are also membrane active as shown by phospholipid vesicle lysis experiments.