Secondary oxidants polymer attached

Apart from sodium hypochlorite, a number of alternative secondary oxidants for TEMPO-mediated alcohol oxidations can be employed. These include cerium (IV) ammonium nitrate (CAN),24 trichloroisocyanuric acid (TCCA),25 oxone ,26 MCPBA,2,3,7 PhI(OAc)2,27 W-chlorosuccinimide,28 sodium bromite,29 electrooxidation,8,21 H5IO626 and a polymer-attached diacetoxybromide (I) complex.30... 

As with fullerenes, carbon nanotubes are also hydrophobic and must be made soluble for suspension in aqueous media. Nanotubes are commonly functionalized to make them water soluble although they can also be non-covalently wrapped with polymers, polysaccharides, surfactants, and DNA to aid in solubilization (Casey et al., 2005 Kam et al., 2005 Sinani et al., 2005 Torti et al., 2007). Functionalization usually begins by formation of carboxylic acid groups on the exterior of the nanotubes by oxidative treatments such as sonication in acids, followed by secondary chemical reactions to attach functional molecules to the carboxyl groups. For example, polyethylene glycol has been attached to SWNT to aid in solubility (Zhao et al., 2005). DNA has also been added onto SWNT for efficient delivery into cells (Kam et al., 2005). 

Oxidative studies on resins with different polymer backbones and functionalities have been performed as accelerated tests.The data is shown in Table 17 for polystyrene and polydiallylamine resins. Although the polydiallylamine resins have a higher initial capacity, they are much more susceptible to oxidative degradation. When the polystyrene resin has a mixture of primary and secondary amino groups or when a hydroxy-containing group is attached to the amine of the functional group, the susceptibility to oxidation is enhanced. Thus one can understand the lower thermal limit for Type II anion resins compared to Type I resins. 

While attached to the resin, the isolated moiety can undergo further chemical manipulation with the PS-thiophenol acting as a linker moiety. Cleavage is achieved by the addition of an amine (primary or secondary), causing nucleophilic displacement from the resin, which also results in additional modification of the molecule (eq 6). The functionalized polymer acts as a traceless linker without the need for oxidation to the sulfone or sulfoxide. 

The coupling of enzymatic and electrochemical reactions has provided efficient tools, not only for analytical but also for synthetic purposes. In the latter field, the possibilities of enzymatic electrocatalysis, for example, the coupling of glucose oxidation (catalyzed either by GOx or GDH) to the electrochemical regeneration of a co-substrate (benzoquinone or NAD+) have been demonstrated [362-364]. An electroenzymatic reactor has also been developed [363-364] to demonstrate the production of biochemicals on a laboratory scale. NAD(P)+ derivatives immobilized by covalent attachment to polymer matrices or protein backbones have been used in enzyme reactors [365, 366]. Another important coenzyme ubiquinone can be regenerated at an electrode [367, 371] and applied to drive secondary enzymatic reactions with the participation of membrane enzymes (e.g. fumarate reductase). 

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