Oxidizing agents, solid supported

Cross-hnked polyacrylamides are a group of hydrophihc solid supports introduced primarily for preparation of biopolymers (Fig. 4). Unhke PS resins, polyacrylamides have excellent swelling capacity in both protic (water, alcohols) and aprotic (dichloromethane, dimethylformamide) solvents [88]. These beads are stable towards bases, acids, and weak reducing and oxidizing agents [89]. Predictably, conditions under which amide bonds are cleaved (i.e., sodium in liquid ammonia) [90] lead to rapid decomposition of the polymer. 

Detailed studies were carried out to determine the effect of C02 as oxidizing agent in alkane dehydrogenation. Iron oxide when supported on suitable solid... 

Coal and many coal-derived liquids contain polycyclic aromatic structures, whose molecular equivalents form radical cations at anodes and radical anions at cathodes. ESR-electrolysis experiments support this (14). Chemically, radical cations form by action of H2SO4 (15,19), acidic media containing oxidizing agents (15,20,21,22), Lewis acid media (18,23-35) halogens (36), iodine and AgC104 (37,38), and metal salts (39,40). They also form by photoionization (41,42,43) and on such solid catalytic surfaces as gamma-alumina (44), silica-alumina (45), and zeolites (46). Radical anions form in the presence of active metals (76). 

The main approach consists of the destabilization of the microemulsion by the addition of an external agent such as tetrahydrofurane (THF), acetone or others. When a solid support, typically a solid oxide or carbonaceous material, is placed in the metal-containing microemulsion, the addition of such a chemical will result in a system destabilization, leading to the deposition of the metal particles on the support. 

Limitations in the use of potassium permanganate and similar oxidizing agents [102-104] have already been mentioned in Section 2.2.2.4. The immobihzation of metallic reagents on solid supports has addressed some of these Hmitations and... 

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