Random and block copolymers containing two different classes of hydrogen-bonding side-chains have been prepared by ring-opening metathesis polymerization. The resulting copolymers can be viewed as “universal polymer backbones” based solely on two competitive hydrogen-bonding pairs. The hydrogen-bonding side chains containing thymine and cyanuric acid-based recognition motifs are shown to self-assemble with their complementary diamido pyridine and isophthalic wedge moieties, respectively, even in the presence of competitive recognition sites, i.e., selective functionalization of the copolymers can be accomplished via a one-step orthogonal self-assembly approach displaying self-sorting in a competitive environment. These results clearly demonstrate the concept of self-sorting in synthetic polymers and suggest the design of complex polymeric materials containing competitive noncovalent interactions.

The design and synthesis of multifunctionalized, architecturally controlled polymers is a prerequisite for a variety of future applications of polymeric materials. On the basis of Nature's use of self-assembly in the creation of biomaterials, this Account describes concepts that were developed over the past 5 years that utilize noncovalent interactions such as hydrogen bonding, ionic interactions, electrostatic interactions, metal coordination, and pi-pi stacking in modification of copolymer side-chains to obtain multifunctional polymeric materials, induce polymer morphology changes, and influence bulk-polymer properties.

A practical, one-pot synthesis of enantiopure unsymmetrical salen ligands is described, using a 1:1:1 molar ratio of a chiral diamine and two different salicylaldehydes. The new synthetic protocol can be readily performed in good yields (60-85%) on a multigram scale with good tolerance toward various functional groups.

We report the synthesis of telechelic poly(norbornene) and poly(cyclooctene) homopolymers by ring-opening metathesis polymerization (ROMP) and their subsequent functionalization and block copolymer formation based on noncovalent interactions. Whereas all the poly(norbornene)s contain either a metal complex or a hydrogen-bonding moiety along the polymer side-chains, together with a single hydrogen-bonding-based molecular recognition moiety at one terminal end of the polymer chain. These homopolymers allow for the formation of side-chain-functionalized AB and ABA block copolymers through self-assembly. The orthogonal natures of all side- and main-chain self-assembly events were demonstrated by (1)H NMR spectroscopy and isothermal titration calorimetry. The resulting fully functionalized block copolymers are the first copolymers combining both side- and main-chain self-assembly, thereby providing a high degree of control over copolymer functionalization and architecture and bringing synthetic materials one step closer to the dynamic self-assembly structures found in nature.

Poly(norbornene) terpolymers containing palladated sulfur‐carbon‐sulfur (SCS) pincer complexes, cyanuric acid, and thymine moieties in their side‐chains were synthesized by ring‐opening metathesis polymerization. Functionalization of the terpolymers was achieved by self‐assembling (i) the Hamilton wedge to the cyanuric acid receptor, (ii) diaminopyridine to the thymine receptor, and (iii) pyridine to the palladated pincer complexes. While all three noncovalent interactions are fully orthogonal to each other in dichloromethane, the employment of a dioxane/chloroform solvent mixture results in the quantitative disassembly of one of the hydrogen bonding recognition units (the Hamilton wedge:cyanuric acid pair) during the metal‐coordination event. This disassembly is completely independent from the diaminopyridine: thymine hydrogen‐bonding pair and allows for the selective removal of one of the side‐chain functionalities. This removal occurs with a switch‐type mechanism: as one functionality is put on (the pyridine), another one (the Hamilton‐wedge receptor) is taken off quantitatively. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1936–1944, 2008