Inorganic supports functionalization

Three approaches have been tested, as already described above for inorganic supports. The first attempts concern the direct reaction of transition metal carbonyls with unmodified organic polymers like poly-2-vinyl-pyridine.61 62 However, this kind of anchoring is restricted to only a few complexes. Various polymers have been functionalized with donor groups 63-72 ligand displacement reactions using these afforded the corresponding immobilized complexes. Finally, tests with modified complexes and unmodified polymers are scarce because of the low stability of these complexes under the conditions of reactions. 

Other covalently bonded catalysts are those on inorganic supports such as silica, molecular sieves (zeolites), and alumina, the complexes being held either directly via the oxygen of surface hydroxy groups or via an intermediate functional group, again especially phosphino. 

To realize surface-bonded initiating sites or their precursors, a variety of methods are applicable. Either organic (polymer) surfaces are irradiated or plasma treated to yield suitable functional groups [187, 195] or inorganic supports are covered with an interlayer of functional polymers bearing the desired groups. However, to gain control over the quantity of surface reaction sites and define the surface chemistry, interlayers of low molar mass a,co-functionalized surface active compounds are suit-... 

Carbon Nanotubes (CNTs) Use of CNTs as inorganic support, focus on electrochemistry as detection method, organic groups and biomolecules as functionalization materials, and their application in sensing. 

Inorganic supports have been used less, but they have undeniable advantages, such as the relatively high oxidative stability of the support. A first attempt was made with salen complexes that are vinyl functionalized at both aromatic rings. By coupling in a thioether, catalyst 7f is obtained. For... 

The functional groups of inorganic supports are usually derived from surface hydration of the metal oxides for example, the silanol... 

Many efforts have been undertaken to graft transition metal complexes onto various supports in order to retain the performance of the soluble catalyst precursors and to allow easy separation of the catalysts from the reaction products. Most studies have been concerned with polymers, particularly with functionalized styrene-divinylbenzene resins. This approach to immobilize homogeneous catalysts has been reviewed, with all the strategies to anchor metal complexes on organic or inorganic supports examined (57-59). 

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