Noncovalently Functionalized Block Copolymers Possessing Both Hydrogen Bonding and Metal Coordination Centers

Abstract

Block copolymers containing both hydrogen bonding and metal coordination sites have been synthesized by ring-opening metathesis polymerization and subsequently functionalized using noncovalent interactions. The resulting block copolymers can be viewed as "universal polymer backbones", as a wide variety of polymers with varying functionalities can be prepared by altering the noncovalent functionalization strategy of the same polymer backbone. The effect of degree of polymerization, block copolymerization, block copolymer composition, and metal coordination on the hydrogen bonding interaction has been investigated. In general, none of these variables have a profound effect on the strength of the hydrogen bonding interactions along the polymer backbones, suggesting that the metal coordination and hydrogen bonding are orthogonal to each other in block copolymers. Finally, the effect of the noncovalent functionalization on the thermal properties of the polymers was investigated. We found that the noncovalent functionalization of all copolymers via hydrogen bonding and/ or metal coordination reduced the glass-transition temperature and the thermal stability of all copolymers.

Bioresorbable vascular scaffolds: The shape of things to come?

“…Thymine and barbituric acid moieties 6 , 7 were selected as end groups, as they represent often used hydrogen bonding motives in supramolecular polymer chemistry by us4, 6–8, 32–36 and others 25, 37–42. Terminating agent ( 8 ) was used as a model system for the introduction of end groups via direct end capping since it is commercial available.…”

Block Copolymers with Functional Inorganic Blocks: Living Addition Polymerization of Inorganic Monomers

“…[12,13] Living polymerizations which lead to block polymers with inorganic elements in the side-group structure have also been subject to major advances. For example, the groups of Schrock, Weck, Chan, Sleiman, and Grubbs have created block copolymers containing sidechain coordination complexes, [14][15][16][17][18] and Jaekle has developed structures with Lewis acidic borane blocks. [19] In all of these cases, the key motivation is the generation of additional functionality by the presence of inorganic blocks or main-chain junction or pendent maingroup or transition elements (Table 1).…”

“…[23] The generalization of addition polymerization protocols for such species will require the selection of side groups which allow sufficient kinetic monomer stability for ready isolation and purification but also for thermodynamically favorable polymerization. coordination of catalytically active transition-metal species, high refractive index [11] Inorganic elements at block junction or star polymer core -RuL x -linker redox-controlled block dissociation for nanopatterning applications [12] -FeL x -or -EuL x -core Fe: facile degradation to form magnetic Fe nanoparticles; Eu: photoluminescent [13] Inorganic elements in the side chain of a block -ZnX 2 or -PdL x precursor to quantum dots (for example, ZnS) and Pd nanoparticles [14] -PdL y site for noncovalent crosslinking [15] -ReL x photoluminescent material [16] -RuL x photoluminescent material [17] -Co 2 (CO) x precursor to Co nanoparticles [18] -BR 2 potential luminescent sensor for Lewis bases (R = dithiophenyl), electroluminescent for light-emissive devices (R = quinolate) [19] [a] T g = glass transition temperature.…”

Side‐chain functionalized supramolecular polymers

“…5). 4, 94, 122–125 A strategy was developed that allows for the functionalization of a single polymer backbone bearing noncovalent receptors with different types of substrate motifs thereby creating fully functionalized copolymers quickly and efficiently. This strategy potentially allows for the synthesis of vast libraries of materials from a single polymer backbone thereby facilitating rapid optimization of polymeric materials.…”

“…This strategy potentially allows for the synthesis of vast libraries of materials from a single polymer backbone thereby facilitating rapid optimization of polymeric materials. The Weck group concentrated their research efforts on polynorbornenes containing pincer ligand‐based metal coordination sites and/or two distinct hydrogen bonding pairs, thymine:diaminopyridine and cyanuric acid:Hamilton's receptor 4, 94, 104, 122–125…”