Cerium charge transfer band

Optical Absorption Spectra and Electronic Structure The optical spectra of all the doubledeckers are listed in Table I, On first glance, Ce(0EP)2 has a "normal" spectrum (7), However, the spectrum shows extra bands and therefore should be called "hyper", A small band appears at 467 nm (maybe a ligand-to-metal charge transfer band), and broad features extend far into the near infrared (NIR), The latter absorption may be due to exciton interactions. Contrary to the known rare earth monoporphyrins (7), it has been shown for the closely related cerium(IV)... 

Charge-transfer spectra of quadrivalent cerium, praseodymium, and terbium showed the position of the first charge-transfer band to be fixed for the metal ion in an oxygen co-ordination of six, but to vary in seven co-ordination as a function of the host lattice. 

Charge transfer bands result whenever an easily oxidized ligand is bound to a trivalent lanthanide ion which can be reduced to the divalent state or when the ligand is bound to one of the tetravalent ions (J0rgensen, 1970). Such transitions are commonly observed in the spectra of complexes of samarium(III), euro-pium(III), thulium(III), ytterbium(III), and cerium(IV). The position of these bands in the spectrum is markedly dependent on the ligand and the metal ion. For example, in the ions RCU the charge transfer bands for europium(III),... 

The same behavior occurs on the Ceo.8Feo,202-5 mixed oxide. It was proven through diffuse reflectance spectroscopy (DRS)-UV-Vis experiments. The spectrum (not shown) exhibited different bands corresponding to different wavelengths. For the pure cerium oxide, the bands at 240, 280, and 340 nm are associated with the f- d transition species of Ce " (0 Ce " ), with charge transfer of Ce for low coordination (0 Ce ), and with an interme-... 

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