Thiol monolayers valency

In this review, we will consider the adsorption of a single species coadsorption phenomena will not be considered, since it is generally impossible to divide the flow of charge among several species. We will present the thermodynamics on which the concept of the electrosorption valency is based, discuss methods by which it can be measured, and explain its relation to the dipole moment and to partial charge transfer. The latter can be explained within an extension of the Anderson-Newns model for adsorption, which is useful for a semi-quantitative treatment of electrochemical adsorption. Our review of concepts and methods will be concluded by a survey of experimental data on thiol monolayers, which nowadays are adsorbates of particular interest. 

The most common procedure for estimating X consists in measuring the thermodynamically significant electrosorption valency l and in evaluating its extrathermodynamic contributions k vkw and g of Eqs. (26) and (27) in order to extract the X value. A more direct extrathermodynamic procedure that relies exclusively on the Gouy-Chapman theory can be applied to the important class of self-assembled thiol monolayers anchored to a metal surface. 

IV. ELECTROSORPTION VALENCY AND PARTIAL CHARGE TRANSFER COEFFICIENT IN SELF-ASSEMBLED THIOL MONOLAYERS... 

Electrosorption Valency of Three Mercury-Supported Thiol Monolayers... 

After making an approximate estimate of the absolute potential difference y/ across the mercury/aqueous solution interphase, let us detennine the electrosorption valency of three mercury-supported thiol monolayers for which uM was measured by potential-step chronocoulometry. As already reported in Sec. IV.1, n-octadecanthiol... 

---