Oxidation of hydrocarbon templates

Plasma Oxidation of Hydrocarbon Templates in Bridged Polysilsesquioxanes Porous Materials by Design... 

Scheme 1. Oxidative removal of hydrocarbon template from bridged polysilsesquioxanes.

As wc know, carbon nanofibers have been widely used in various areas, such as in electronic components, as polymer additives, for gas storage, and as catalyst support [94]. Via the decomposition of hydrocarbons or carbon monoxide over Ni, Co or Fe catalysts, a large quantity of carbon fibers can be produced. Moreover, these carbon fibers with different sizes and shapes, such as straight, bent, thin and helical, etc., could be synthesized by controlling the reaction conditions [95-99]. With carbon nanofibers as template, Ueda and co-workers prepared a number of single and binary transition metal oxide nanofibers and/or nanotubes, including LaMnOs and LaFeOs nanofibers and nanotubes [99-102]. 

For the anodic substitution of unactivated CH-bonds, some fairly selective reactions for tertiary CH-bonds in hydrocarbons and y—CH-bonds in esters or ketones are available [85-87]. However, in some cases, a better control of follow-up oxidations remains to be developed. Chemically, a number of selective reactions are available, such as the ozone on silica gel for tertiary CH-bonds [88], the Barton or Hoffmann-LoefHer-Freytag reaction for y-CH-bonds [89], and for remote CH-bonds, Cprop)2NCl/H [90, 91], photochlorination of fatty acids adsorbed on alumina [92] or template-directed oxidations [93]. 

Metal-assisted cycloaddition reactions involving meso-perfluoroalkylated porphyrinic templates define a versatile methodology for the syntheses of both cofacial porphyrin structures and facially-functionalized (porphinato)metal species [62], and corresponding compositions that offer new opportunities for development of small molecule redox catalysts [63, 64]. Scheme 21 shows the versatile metal-mediated [2+2+2] cycloaddition step for the isolation of meso-perfluoroalkyl cofacial porphyrins that results in the purified indane complexes in 10-12 % yields. These cofacial complexes are directly applicable to multi-electron redox reactions such as oxygen or nitrogen reduction and even hydrocarbon oxidation. 

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