Biophysical Implications

Lyotropic numbers N o, Table 5.1, were assigned to ions in the 30s of the last century by Buchner and Voet (Buchner et al. 1932 Voet 1937a, 1937b) according to their effects on colloidal systems. The lyotropic series has nowadays been to some extent superseded by the Hofmeister series, with which it is taken to be practically synonymous, but it is not so exactly. For the alkali metal cations and the halide anions the lyotropic numbers obtained from colloidal phenomena are linearly related to their enthalpies of hydration. Voet (1937a) concluded that the lyotropic series are simply related to the electric field strengths of the ions. Note that the Myo values for the alkali metal cations are not commensurate with those of the alkaline earth cations and with those of the anions. 

it is urged on the researchers on solution chemistry and biophysics to call what they studied specific ion effects if the study does not pertain to aqueous electrolytes (ions) near surfaces at appreciable concentrations (where the Hofmeister series or effect is appropriate) nor should they invoke kosmotropic and chaotropic properties if their study does not pertain to dilute aqueous electrolytes (ions) in homogeneous solutions. The fact, that the order in a series of ions correlates with the Hofmeister series or with the series of ions according to their kosmotropic and chaotropic properties does not justify per se having such epithets in the title of the paper rather than specific ion effects with which the paper really deals. This field was 

---

Zdravkovic, S., Sataric, M.V., and Tuszynski, J.A., Biophysical implications of the Peyrard-Bishop-Dauxois model of DNA dynamics, J. Comput. Theor. Nanosci., 1, 171-181, 2004. 

Y. Marcus, Ions in Water and Biophysical Implications, Springer, Dordrecht (2012). 

The energy of the ion pair state P+B" is expected to be close to P, however, our ignorance of the detailed energetics (and other dynamic parameters) precludes an a-priori theoretical prediction of the primary ET mechanism and one has to rely on a phenomenological a-posteriori analysis of the experimental data in terms of ET theory. All mechanisms proposed for the primary ET attribute a special role to B, which involve (I) A one-step superexchange mechanism.3 i3 (jj) Two-step ET with P+B"H as a real chemical intermediate. (III) The parallel sequential-superexchange mechanism, which provides a unified scheme that includes both the unistep and sequential mechanism as limiting cases. Are these mechanisms relevant for the primary ET events in the RC, and what are the biophysical implications of the mechanism of the primary ET ... 

---