Polynorbomene synthesis

With the growing interest for the polynorbomene, photoresist polymer, and cyclic olefin copolymer, the synthesis norbornene or bicyclo[2,2,l]-2-heptene (NBN) has drawn significant attention because it is one of the most important precursor for these materials. Norbornene is produced by the reaction between ethylene and cyclopentadiene (CPD) via the Diels-Alder condensation process at elevated temperature and pressure [1,2]. 

In addition to block copolymer synthesis by subsequent polymer growth along one polymer chain, Eq. (21), and the reaction sequence of Eqs. (19, 22—24), preformed polymer blocks can be linked via reactive end groups. Polynorbomene with one titanacyclobutane end group was reacted in a Wittig-type reaction with... 

Ferrocene-functionalized norbomene monomers have been copolymerized with norbomene attached to a gold nanoparticle through alkanethiol bonds (Scheme 2.49).250 This polymerization was a three-step synthesis where the first step was the metathesis of the norbomene on the gold nanoparticle with one equivalent of the catalyst. This step was then followed by the addition of monomer 186, and the addition of monomer 187 20 minutes later. This methodology could be used to prepare nanoparticles with varying layers of polynorbomene. 

Finkelshtein ES, Makovetskii KL, Gringolts ML, Rogan YV, Golenko TG, Starannikova LE, Yampolskii YP, Shantarovich VP, Suzuki T. Addition-type polynorbomenes with Si(CFt3)3 side groups Synthesis, gas permeabihty, and free volume. Macromolecules 2006 39(20) 7022—7029. 

A second method for the synthesis of organometallic polynorbomenes containing a bound azo dye involved the reaction of T -chlorotoluene- n -cyclopentadienyliion complex 21 with bifunctional azo dyes to yield the azo dye-containing organoiron compounds, which wctc then further reacted with 5-norbomene-2-carboxylic acid (16) to form the azo dye functionalized norbomene monomers, 24, shown in Scheme 7.7. 

The multifunctional initiator approach was also used for the synthesis of stars by ROMP. Carbosilane dendrimers bearing mthenium complexes on their surface (Scheme 59) were prepared and used to synthesize 4- and 8-arm polynorbomene stars. End-group analysis by NMR revealed that well-defined stmctures were obtained. 

Many different support materials were developed [3, 4] since the original use by Merrifield of a polystyrene-based support material for polypeptide synthesis [5]. The work of Merrifield is described in Chap. 8 (see section on proteins). Beads of copolymers of styrene with divinyl benzene are available commercially and have been widely used as supports for many reactions. Many other polymeric materials are also used. These can be various other type of copolymers of styrene or with other polymers. The list includes cellulose, starch, polyalkanes, polyamides, poly(glycidyl methacrylate), polyisobutylene, polynorbomene, polyacrylamide, and others. In some instances, even glass was used. The more prominent support materials are presented below. 

Ring-opening metathesis polymerization has also been exploited to build blocks from cyclic olefins, especially polynorbomene (5). The development of ring-opening metathesis polymerization for block copolymer synthesis has recently been facilitated by the introduction of functional group tolerant metathesis catalysts (21). 

We have reported that norbornene monomers functionalized with arene complexes also undergo ring-opening metathesis polymerization to produce the corresponding cyclopentadienyliron-coordinated polynorbomenes. Scheme 13 shows the synthesis of polymers containing aromatic ether sidechains functionalized with organoiron moieties. ... 

Katsumata T, Shiotsuki M, Sanda F, Masuda T (2009) Synthesis and properties of polynorbomenes bearing oligomeric siloxane pendant groups. Polymer 50 1389-1394... 

Katsumata T, Satoh M, Wada J et al (2(K)6) Polyacetylene and polynorbomene derivatives carrying TEMPO. Synthesis and properties as OTganic radical battray materials. Mactomol Rapid Commun 27(15) 1206-1211... 

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