Electrophilic reactions nucleophile capping

Addition of either nucleophilic or electrophilic metallic species can result in the capping of triangular- or square-metal faces in carbonyl clusters. These redox reactions provide high yield syntheses of higher nuclearity clusters and somewhat resemble surface reconstruction on metals. With a few examples,... 

The goal of chemical modification of phenolics is the improvement of chemical and physical properties and to tailor the polymer to specific applications. Phenolics can be modified during synthesis by use of substituted monomers or monomer mixtures and after synthesis by electrophilic ring substitution, nucleophilic hydroxyl group capping, and reactions with compounds of boron, phosphorous, silicon, and titanium. 

Although the methacrylate polymer enolate ion is centered on a hindered tertiary carbon, it is reactive enough to participate in nucleophilic substitution reactions with suitably reactive electrophiles. Such reactions must necessarily be carried out at or near -78°C to ensure that the anion is not inactivated by the thermal cyclization reaction. Typical of such reactions is that with-vinyl benzyl iodide which gives the styryl-capped oligomer 14. 

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