Facile Preparation of Supramolecular H-Shaped (Ter)polymers via Multiple Hydrogen Bonding

A well-defined Hamilton wedge (HW) midchain functionalized block copolymer, i.e., polyethylene glycol- b -polystyrene (PEG-HW-PS, M n,GPC = 5600 Da, PDI = 1.03), was successfully synthesized via a combination of atom transfer radical polymerization (ATRP) and copper-catalyzed azide alkyne cycloaddition (CuAAC). An α,ω-cyanuric acid (CA) difunctional linear homopolymer poly( n -butylacrylate) (CA-P n BA-CA, M n,GPC = 8100 Da, PDI = 1.09) was concomitantly prepared via reversible addition–fragmentation chain transfer (RAFT) polymerization. Supramolecular H-shaped macromolecules were—for the first time—prepared through supramolecular self-assembly between HW and CA recognition motifs to generate (PS- b -PEG) · P n BA · (PS- b -PEG) and (PS- b -PS) · P n BA · (PS- b -PS) in CH 2 Cl 2 or dichloromethane- d 2 at ambient temperature. The self-assembly process (at a total concentration of the two species of close to 4.5 mM) was evidenced by proton nuclear magnetic resonance ( 1 H NMR) spectroscopy, diffusion-ordered NMR spectroscopy (DOSY), and dynamic light scattering (DLS) analyses. The results derived via DOSY NMR experiments and DLS combined with a Job plot analysis and in-depth NMR titration experiments indicate that the formation of supramolecular H-shaped macromolecules in 2:1 stoichiometry is efficiently occurring via the employed complementary recognition motifs with high binding constants (between 1.2 and 1.5 × 10 5 L mol –1 at ambient temperature).