Reorganization of solvents

There may be considerable reorganization of solvent molecules around the... 

The partitioning of [1+] between addition of solvent and deprotonation was discussed in Section 2, where it was suggested that the observed ratio of kjkp = 60 in 50/50 (v/v) trifluoroethanol/water underestimates the relative chemical barriers for ks and kp. This is because the addition of solvent is limited by rotational reorganization of solvent, ks = reorg 1011 s-1.21 Use of the larger value of (ks)chem = 1012 s 1 estimated for the addition of solvent that is prepositioned to react with [1+]21 gives kjkp = 600. The latter ratio is close... 

It is important to note that the rate of solvent relaxation depends on the solvent viscosity. If the time required for the reorganization of solvent molecules around... 

First the oxidant (0) and reductant (R) come together to form a precursor complex. Activation of the precursor complex, which includes reorganization of solvent molecules and changes in metal-ligand bond lengths, must occur before electron transfer can take place. The final step Is the dissociation of the ion pair into product ions. 

The necessary reorientation or reorganization of solvent dipoles also creates a barrier to electron transfer. An attempt is made to illustrate the point schematically in Figure 2. Rather than try to show individual solvent molecules and their dipole orientations, the decrease in ion-solvent interaction between a +3 and a +2 ion is illustrated by the more tightly drawn circle around the +3 ion. The circles are a schematic attempt to illustrate the interactions between the surrounding solvent sheath and the ionic charges. 

Another distortion reason is related to the charging of the double layer formed at the electrode-solution interphase. The reorganization of solvent dipoles and ions at the solution phase layer adjacent to the electrode as a response to the application... 

The nature of the quenching mechanism can be easily confirmed by recording the emission spectrum in a frozen solution (EtOH/MeOH mixture (9 1) at liquid nitrogen temperature). Under these conditions, the relative decrease in fluorescence intensity expressed as I /Iq is equal to 0.82, while at room temperature it is 0.23. Such a reduction in quenching efficiency in a frozen solution is characteristic of an electron transfer mechanism. In fact, immobilization of the solvent molecules in a frozen matrix prevents the reorganization of solvent molecules sur-... 

An additional effect of applied bias is the reorganization of solvent ions to minimize the energy of the system. A more negative... 

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