Chemistry Reference
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Figure 5.7 Functionalization strategies of copolymer 4 based on multiple hydrogen bonding
interactions.
Copolymer 4 (Fig. 5.7) based on polynorbornene was functionalized with two differ-
ent hydrogen bonding side chains based on thymine and cyanuric acid recognition
groups (Burd and Weck 2005). They demonstrated that the thymine and cyanuric
acid units were able to self-assemble with their complementary 2,6-diamimopyridine
and Hamilton wedge moieties, respectively, even in the presence of competitive
recognition sites. Thus, selective functionalization of the copolymers can be
accomplished by a one-step orthogonal self-assembly approach.
The selective self-assembly of a receptor molecule with its complementary recog-
nition unit in the presence of a competitive recognition unit has been described as
self-sorting in the literature. Using the described system containing two hydrogen
bonding units, Burd and Weck (2005) were able to prove the concept of self-
sorting in synthetic polymers for the first time and suggest the design of complex
polymeric materials containing competitive noncovalent interactions.
5.3.4. Terpolymer Functionalization Strategies: Combing
Hydrogen Bonding, Metal Coordination, and
Pseudorotaxane Formation
Random polynorbornene-based terpolymer 5 (Fig. 5.8) functionalized with
SCS palladated pincer complexes, dibenzo[24]crown-8 (DB24C8) rings, and 2,6-
diaminopyridine units was synthesized by ROMP (South et al. 2006). The palladium
complex serves as the anchoring unit for metal coordination, 2,6-diaminopyridine as
the DAD hydrogen bonding moiety, and DB24C8 as the precursor for pseudoro-
taxane formation, which has been studied extensively by Stoddart and his group
