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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.
Protein folding problem: Is it possible to predict the secondary, tertiary and quaternary structure of a polypeptide sequence based solely on the sequence and environmental information? Inverse protein-folding problem: Is it possible to design a polypeptide sequence which will adopt a given structure under certain environmental conditions?
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.
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.
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 ...
As an example from inorganic chemistry the permanganate ion, MnO − 4, in aqueous solution has an intense purple colour due to an O → Mn ligand-to-metal charge transfer band (LMCT) in much of the visible region. [22] This band shows a progression in the symmetric Mn–O stretching vibration. [23]
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.
Compounds that obey the 18-electron rule are typically "exchange inert". Examples include [Co(NH 3) 6]Cl 3, Mo(CO) 6, and [Fe(CN) 6] 4−.In such cases, in general ligand exchange occurs via dissociative substitution mechanisms, wherein the rate of reaction is determined by the rate of dissociation of a ligand.