Transfer, intervalence

Hush N S 1967 Intervalence-transfer absorption. Part 2. Theoretical considerations and spectroscopic data Prog. inorg. Chem. 8 391... 

Intervalence transfer absorption, part I qualitative evidence for intervalence transfer absorption in inorganic systems in solution and in the solid state. G. C. Allen and N. S. Hush, Prog. Inorg. Chem., 1967, 8,357-389 (116). 

D. Intervalence-Transfer Bands for Mixed-Valence Oligo(ferrocenylene)s... 

All compounds were measured at room temperature in air between Au electrodes inside a Faraday cage. IVT = maximum of the optical InterValence Transfer or intramolecular charge transfer band. RR Rectification Ratio. Survives cycling means RR does not decrease with cycling of IV measurements. AR or anti-AR indicates whether electron flow is from A to D (AR) or from D to A (anti-AR)... 

Allen, G. C. and Hush, N. S., Intervalence-Transfer Absorption. Part I Qualitative Evidence for Intervalence Transfer Absorption in Inorganic... 

Mixed-valence chemistry was reviewed in the late 1960 s both by Robin and Day (4) and by Hush (5). Their work provided the beginnings of a theoretical background for understanding the properties of mixed-valence compounds including the low energy absorption bands which have been termed Intervalence Transfer (IT) or Metal-Metal Charge Transfer (MMCT) bands. 

Where thermal electron transfer can occur, there is also always a corresponding optical transfer, which I have termed intervalence transfer (19-21). The principle is illustrated in a single coordinate representation in Figure 2. Clearly, it will be possible to relate thermal to optical transfer probabilities, and, hence, to predict the rate of one process from parameters obtained for the others. The connection is, in fact, a very close one, as indicated schematically in Figure 3. 

The intervalence transfer extinction coefficient, e, is proportional to a frequency-dependent conductivity, o, with a... 

Figure 6. Temperature dependence of half-width of intervalence transfer absorption for [(NHS)sRu(4-cyanopyridine) Ru(NHs)5]5 mixed-valence (24, 25).

One experimental source of these essential data (for mixed-valence systems) is the intervalence transfer absorption band. The moments of the envelope (particularly the first and second moments) can be interpreted to yield values for x and (from a study of temperature dependence) for an effective coupling frequency. The study of effects of solvent variation can also lead to separation of x into intramolecular and environmental components. ... 

Table 4. EPR and Intervalence Transfer Transition Parameters for Half Met L Hemocyanlns...

Figure 10 Optical intervalence transfer in a symmetric mixed-valence compound. Correlation between spectroscopic and kinetic parameters.

Smith, G. Strens, R. G. J. (1976) Intervalence transfer absorption in some silicate, oxide and phosphate minerals. In The Physics and Chemistry of Minerals and Rocks. (R. G. J. Strens, ed. J. Wiley Sons, New York), pp. 583-612.. 

Many of these complexes are deeply colored and their electronic spectra contain very strong intervalence transfer bands in the visible, due to electron transfer from B to A (Robin and Day, 1967). They also show magnetic coupling and they have semiconducting properties. They are stable in air and in acid solutions, but they dissociate in alkali. They can be reversibly oxidized, whereby B gives up an electron and goes to a higher oxidation state, and the intense color disappears. 

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