Ligand-metal charge transfer examples

Using chemistry similar to that just discussed for Cu +, we have shown that many other transition metal ions, including Pd +, Pt +, Ni +, and Ru +, can be extracted into the dendrimer interiors [59,83,84]. For example, a strong absorption peak at 250 nm ( =8000 cm ) arising from a ligand-to-metal-charge-transfer... 

The photoelectrochemical kinetic scheme involves a photochemical reaction that is followed by an electrochemical reaction. The photochemical reaction is used to produce or deactivate the reducing agent. Catalytic metallic nuclei are formed in the subsequent electrochemical reaction. For example, the Fe reducing agent (Red) needed for reaction (8.24) is generated in the photochemical reduction of complexed Fe ions. This redox photolysis is the ligand-to-metal charge transfer with the overall reaction of oxidation of [ 204] ... 

We focus initially on the photochemical behaviour of complexes of Fe(III) with simple carboxylic acids and give particular attention to oxalic acid. This compound is prevalent in atmospheric aerosols [28], provides a simple example of environmentally important light-mediated ligand-to-metal charge transfer (LMCT) processes which result in ligand decarboxylation [27] and is used to initiate the degradation of contaminants both in the absence and presence of added hydrogen peroxide (via the so-called modified photo-Fenton process [29,30]). In addition, the photochemistry of Fe(III)-oxalate complexes has been studied in detail, as it is the basis of... 

The absorption spectroscopy in the UV-Vis-NIR is especially rich for the actinides, allowing for fairly simple determinations of the metal oxidation state. The primary absorption bands result from f f transitions, f d and ligand-to-metal charge transfers. The f — f transitions are typically weak since they are forbidden under the LaPorte selection rules. Distortions in symmetry allow for relaxation in these rules and bands in the visible to near-infrared range result. Complexes that contain an inversion syimnetry, for example Pu02CLt, have weaker f- -f transitions (e < 20 cm ). The direct interactions of the 5f orbitals... 

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