Chemical synthesis, polymers redox reactions

Electrocatalysis is a type of electrosynthesis that uses surface modified electrodes, or mediators/electrocatalysts to facilitate the redox reaction. Meyer reported the design and synthesis of a chemically modified electrode that consists of a thin polymer film with covalently attached redox sites,designed to facilitate rapid electron transport for electrocatalysis. Complexes of Fe, Ru, Os, Re, and Co were synthesized in such a way that when electrochemically reduced, they reacted to form smooth electroactive polymer films that adhered well to the working electrode to form a chemically modified electrode designed for electrocatalysis. 

For crystallization of (TSeT)2halides in a polymer film a selective chemical redox reaction had to be found. The thermally induced oxidation of TSeT with organic perhalides is a new synthesis pathway which offers access to the reaction and crystallization route. This reaction yields pure 2 1 complexes. The driving force is the insolubility of the formed CT-complex salt, the reaction proceeds during the increase of concentration due to solvent evaporation. Fig. 2 shows a typical experiment for the in-situ crystallization from a diluted solution. A solution of TSeT, polymer and solvent is mixed quickly with an excess of a... 

Santora et al developed an MIP, which was capable of accelerating a similar reaction, i.e., linking cyclohexadiene with a a P-unsaturated carhonyl compounds (cyclic Diels-Alder reaction). Furthermore, redox reactions, transacylations or the synthesis of lactons have been catalyzed by MIP (see also Table 7.6). For the aldol-condensation of acetophenone with benzaldehyde, a polymer imprinted with a dibenzoylmethane/Co complex was utilized. These approaches may just be the beginning of a broad implementation of catalyticaUy active MIP in chemical synthesis. 

The successful assembly of organic compounds on a solid support represents only part of the challenge in SPOS. After completion of synthetic sequence, the compounds must be cleaved from linkers attached to polymer by a chemical or photochemical reaction, for example, treatment of a polymer-bound compound with acids, bases, nucleophiles, redox reagents, and even photons. Acid-labile linker and amine-cleavable Marshall linker are two major classes of hnkers used in combinatorial synthesis. 

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