Noncovalent wedging effect catalyzed the cis to syn transformation of a surface-adsorbed polymer backbone toward an unusual thermodynamically stable supramolecular product

The significant influence of noncovalent interactions on catalytic processes has been recently appreciated but is still in its infancy. In this report, it is found that wedging Me-PTCDI (small-molecule) between the alkyl chains of PffBT4T-2OD (polymer) and a graphite substrate can reduce the energy barrier of flipping over the surface-adsorbed alkylthiophene group from the to conformation, revealing the catalytic role of Me-PTCDI a noncovalent wedging effect. The wedging of Me-PTCDI brings the interactions between the alkyl chains and substrate to a very weak level by lifting up the alkyl chains, which eliminates the major hindrance of the flipping process to one main factor: the torsion of the dihedral angles of the thiophene group. The Me-PTCDI/ PffBT4T-2OD arrangement shows unusual stability compared to the one because the conformation allows the alkyl chains to construct dense lamella and facilitates interactions between Me-PTCDI and the PffBT4T-2OD backbones. The results are helpful for boosting the development of noncovalent catalysis and bottom-up fabrications toward devices functionalized at a molecular level.