Inverted region, electron transfer

Figure 2 Energy surfaces corresponding to the normal, barrierless, and inverted electron-transfer reactivity regions of Marcus theory.

Guldi D M and Asmus K-D 1997 Electron transfer from Cjg D2) and Cjg C2 ) to radical cations of various arenes evidence for the Marcus inverted region J. Am. Chem. See. 119 5744-5... 

Gould I R, Ege D, Mattes S L and Farid S 1987 Return electron transfer with geminate radical ion pairs - observation of the Marcus inverted region J. Am. Chem. Soc. 109 3794-6... 

Electron transfer corresponds to the transition from U, to at the transitional confignration P. AF is the free-energy of the transition. The lower free-energy snrface of the final state corresponds to the inverted region. 

Two situations may be distinguished according to whether the electron transfer step of the stepwise mechanism lies in the normal region or in the inverted... 

The relationship between electron transfer in the normal and inverted regions is illustrated in Figure 3 for the case of quenching of Ru(bpy) + by a nitroaromatic quencher. Excitation... 

One striking prediction of the energy gap law and eq. 11 and 14 is that in the inverted region, the electron transfer rate constant (kjjj. = ket) should decrease as the reaction becomes more favorable (lnknr -AE). Some evidence has been obtained for a fall-off in rate constants with increasing -AE (or -AG) for intermolecular reactions (21). Perhaps most notable is the pulse radiolysis data of Beitz and Miller (22). Nonetheless, the applicability of the energy gap law to intermolecular electron transfer in a detailed way has yet to be proven. 

Schmickler W, Tao N (1997) Measuring the inverted region of an electron transfer reaction with a scanning tunneling microscope. Electrochim Acta 42 2809-2815... 

The inverted region is so-called because the rate of the electron-transfer process decreases with increasing thermodynamic driving force. 

The PET process in the dyad is located in the normal region of the Marcus curve, while the back-electron transfer from Q0 to ZnPor+ is in the Marcus inverted region (Figure 6.27). 

The inverted region in electron transfer reactions is studied for the reaction of electronically-excited ruthenium(II) tris-bipyridyl ions with various metal(III) tris-bipyridyl complexes. Numerical calculations for the diffusion-reaction equation are summarized for the case where electron transfer occurs over a range of distances. Comparison is made with the experimental data and with a simple approximation. The analysis reveals some of the factors which can cause a flattening of the In k versus AG curve in the inverted... 

The best way to search for the existence of an inverted region (if any) would be to use a single electrochemical electron transfer reaction in one solvent medium at a particular electrode and determine the effect of high overpotential on the reaction rate or the current density. Many experiments were carried out at organic spacer-covered ( 2.0 nm thick) electrodes to search for the inverted region for the outer-sphere ET reactions however, no inverted region was observed." ... 

The further improvement of the product yield (100%) was achieved by employing AcrPh + instead of AcrH + and this can also be ascribed to the slower back-electron transfer rate for the former than the latter [109]. In the Marcus-inverted region, the back-electron transfer becomes slower with increasing the driving force. Because the EZx value of AcrPh" (E°x versus SCE = - 0.55 V)... 

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