Functionalization at the central position of vinyl polymer chains: highly associable multipoint hydrogen bonds for complementary self-assemblies.

This paper deals with the precision introduction of a multiple hydrogen-bonding site of a high association constant at the central position of a vinyl polymer chain for complementary self-assemblies. The interactive site consists of an array of hydrogen donors (D) and acceptors (A) to induce a multiple and highly associable interaction with a complementary counterpart. A bifunctional initiator (Cl-DADDAD-Cl) for metal-catalyzed living radical polymerization is thus designed and synthesized to embed a "Hamilton receptor" (DADDAD) between two terminal chlorides (Cl). In the presence of a ruthenium complex, the dichloride gives controlled polymers (Cl∼∼∼DADDAD∼∼∼Cl, ∼ ∼ ∼: polymer backbone) of narrow molecular weight distributions (Mw/Mn < 1.2) from common monomers such as styrene and methyl methacrylate (MMA). The receptor-decorated polystyrene recognizes complementary associable molecules and polymers carrying an ADADA unit (ADADA-Anthracene and ADADA-PMMA) to form self-assemblies where the association constant is as high as K(ass) ≈ 8000 m(-1).