Polyester dendron

ALIPHATIC POLYESTER DENDRONS AND DENDRIMERS BASED ON 2,2-BIS-HYDROXYMETHYLPROPIONIC ACID... 

Moore and Suslick conducted shape-selective catalysis with metalloporphyr-ins 12 bearing sterically demanding polyester dendrons (a, b, Fig. 6.38) [58, 59]. 

A radical copolymerization of the styryl monomer carrying Percec-type polyether dendrons (G1-G2), and the maleimide monomer carrying polyester dendrons (G1-G2), provided access to various styrene-co-maleimide dendronized polymers (Figure 37.5). The molar mass of the polymer, Gl-olt-Gl and G2-alt-G2 was found to be 1320 kDa (DPw = 1230, one repeat unit equals one pair of comonomers) and 708 kDa (DP = 280), respectively, by employing a GPC-TALLS... 

To obtain segment block dendiimers, Kose et al. (2008) utilized Frechet type dendrons appended with electron rich furan at the focal point and a complementary set of polyester dendrons containing the electron de cient maleimide group at the focal point Combination of these two complimentary dendrons was accomphshed by heating in benzene to obtain thermoresponsive segment block dendrimers in good yields (Hg. 12.27). The dendiimers fell apart upon heating them to 110°C. 

In an attempt to develop synthesis of QDs using dendrimers as template, amino-polyester dendrons were used for t plating and stabilizing of CdS nanoparticles on the surface of single-wall carbon nanotubes (SWNTs) (Fig. 6.19). Attachment to SWNTs can be achieved by focal group while the interior space of the dendron serves for nanoparlicle formation. The obtained CdS nanoparticles with diameter of 1.4 nm were stable for more than 90 days at 25°C. It has been suggested that these characteristics may be useful for fabricating molecular electronic devices [55]. 

Frechet and coworkers explored the synthesis of polyester dendrons on solid support. These dendrons, based on 2,2-bis(hydroxymethyl)propanoic acid monomers, were assembled up to the fourth generation on poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) resin and decorated with chiral proline derivatives (Scheme 15.15). T vo methods for preparation of these materials were reported. The solid-phase divergent approach yielded polymer with higher loading but a less precise architecture than the second approach. The second approach, the divergent synthesis of the dendrons in solution, followed by the focal point deprotection and then attachment to the solid support, led to well-defined structures on the polymer, but relatively low loading. 

Scheme 15.15. Synthesis of polyester dendrons on solid support.

The use of dendronized polymers as CSPs was successfully established by Frechet and coworkers. The polymer-bound polyester dendrons (not chiral themselves, see Section... 

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