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Absorption spectrum of an aqueous solution of potassium permanganate, showing a vibronic fine structure in the LMCT band. The tetraoxides of d 0 metal centers are often deeply colored for the first row metals. This coloration is assigned to LMCT, involving transfer of nonbonding electrons on the oxo ligands to empty d-levels on the metal.
A well-known example is the complex formed by iodine when combined with starch, which exhibits an intense purple charge-transfer band. This has widespread use as a rough screen for counterfeit currency. Unlike most paper, the paper used in US currency is not sized with starch. Thus, formation of this purple color on application of an iodine ...
The charge-transfer complex that forms between the metal ions and the dendrimer exhibits a ligand-to-metal charge transfer, or LMCT, band in the UV-Vis spectrum, indicating that a complex has formed. The specific wavelength of occurrence for these LMCT peaks are different for each metal.
For example, the colour of chromate, dichromate and permanganate ions is due to LMCT transitions. Another example is that mercuric iodide , HgI 2 , is red because of a LMCT transition. A metal-to-ligand charge transfer (MLCT) transition will be most likely when the metal is in a low oxidation state and the ligand is easily reduced.
Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow salt. [4] It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores sphalerite and wurtzite, which are the major economic sources of cadmium.
In chemistry, a molybdate is a compound containing an oxyanion with molybdenum in its highest oxidation state of +6: O − −Mo(=O) 2 −O −. Molybdenum can form a very large range of such oxyanions, which can be discrete structures or polymeric extended structures, although the latter are only found in the solid state.
It is a red-brown paramagnetic solid. It is the potassium salt of tetraperoxochromate(V), one of the few examples of chromium in the +5 oxidation state and one of the rare examples of a complex stabilized only by peroxide ligands. [2] This compound is used as a source of singlet oxygen. [1]
Henry Taube FRSC (November 30, 1915 – November 16, 2005) was a Canadian-born American chemist who was awarded the 1983 Nobel Prize in Chemistry for "his work in the mechanisms of electron-transfer reactions, especially in metal complexes."