Surface complex formation photoredox reactions

The various elementary steps involved in the surface photoredox reaction, leading to dissolution of hematite in the presence of oxalate, are outlined in Figure 12.10. The two-dimensional stmcture of the surface of an iron(III) hydroxide given in this figure is highly schematic. The charges indicated correspond to relative charges. An important step is the formation of a hypothetical bidentate, mononuclear surface complex. With pressure jump relaxation technique, it has... 

As discussed in the previous section, a ligand-to-metal charge-transfer transition of the surface complex (mechanism 1) and/or a Fe -O"11 charge-transfer of hematite (mechanism 2) are the oscillators involved in the surface photoredox reaction, leading to reductive dissolution of hematite in the presence of oxalate. The elementary steps and the derivations of the rate expressions of photochemical surface iron(II) formation of mechanism 1 and 2 are outlined in reactions 16-19, Eqs. 20-26, reactions 27-31, and Eqs. 32-37, respectively. 

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