Case Study Polymerization of 4-Substituted Aromatic Enynes

A more complete discussion of charge distributions is deferred until Chapter 9. The performance of HF theory for other molecular properties is also presented in more detail there. 

5 Case Study Polymerization of 4-Substituted Aromatic Enynes 

Synopsis of Ochiai, Tomita, and Endo (2001) Investigation on Radical Polymerization Behavior of 4-Substituted Aromatic Enynes. Experimental, ESR, and Computational Studies . 

One strategy for making highly functionalized polymers is first to cany out polymerization of a system bearing functionalizable appendages, and then after polymerization to react those appendages to introduce new functionality into the polymer. Such an approach can be advantageous in instances where the monomer that would in principle lead directly to the functionalized polymer fails itself to be useful as a polymerization substrate. 

A factor that affects the kinetics of the polymerization, and, more critically, the utility of the monomer in copolymerizations with other monomers, e.g., methyl methacrylate, is the stability of the radical formed from addition of the growing polymer chain to the vinyl terminus. In order to gauge the stabilizing effect of the phcnylethynyl group, and the sensitivity of the stabilization to substitution at the para position of the aromatic ring, Ochiai and co-workers carried out calculations at the UHF/3-21G level to evaluate 

The spin density calculation, which analyzes the difference between each atom s Mulliken population (see Section 9.1.3.2) of a and ft electrons, indicated the unpaired electron to be highly delocalized, with populations on the ortho and para carbons of the phenyl 

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CASE STUDY POLYMERIZATION OF 4-SUBSTITUTED AROMATIC ENYNES... 

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