Sterically controlled recognition of macromolecular sequence information by molecular tweezers.

摘要: Sequence-specific binding is demonstrated between pyrene-based tweezer molecules and soluble, high molar mass copolyimides. The involves complementary π−π stacking interactions, polymer chain-folding, hydrogen bonding extremely sensitive to the steric environment around pyromellitimide binding-site. A detailed picture of intermolecular interactions involved has been obtained through single-crystal X-ray studies complexes with model diimides. Ring-current magnetic shielding polyimide protons by pyrene “arms” molecule induces large complexation shifts corresponding 1H NMR resonances, enabling specific triplet sequences be identified their shifts. Extended comonomer (triplets triplets in which monomer residues differ only presence or absence a methyl group) can “read” mechanism multiple adjacent diimide within copolymer chain. The...