Organic adlayers

Pastor E, Castro CM, Rodriguez JL, Gonzalez S. 1996. On-line mass spectrometric studies on the interaction between organic adlayers on platinum. Part 1. Consecutive adsorption of formic acid and propargyl alcohol. J Electroanal Chem 404 77-88. 

Self-organized adlayer of calix[4]arene on Au(lll) has been obtained by potential-controlled adsorption [327]. In situ STM... 

C. Buess-Herman, S. Bare, M. Poelman, Ordered organic adlayers at electrode surfaces in Interfacial Electrochemistry. Theory, Experiment and Applications (Ed. A. Wi ckowski), Marcel Dekker, New York-Basel, 1999, p. 427. 

A more complete review of all previous experimental work on the structure and orientation of organic adlayers grown by OMBD on solid substrates is beyond the scope of this chapter. The literature up to the year 2004 has been reviewed previously in the paper by Witte and Woll [30] as well as in the papers by Schreiber [31] and Forrest [32]. 

The adsorption of these molecules has also been investigated on various iodine-modified electrodes such as I/Ag(lll), I/Pt(lll) and I/Rh(lll). Highly ordered adlayers of TMPyP were found to form on I/Au(l 11) and I/Ag(l 11), whereas less-ordered adlayers formed on I/Pt(lll) and I/Rh(lll) [41]. The surface mobility of iodine on Pt(l 11) is very slow, as shown in Fig. 1(b). TMPyP is adsorbed on I/Pt(l 11) as isolated molecules with a disordered arrangement These results suggest that the surface mobility of the iodine adatoms also plays an inqmrtant role in the ordering process of the organic adlayer. 

Fig. 21 A Single voltammetric scans of the reductive desorption for BPl to BP4 mono-layers on Au(lll)-(1 X 1) in 0.1 M NaOH after immersion at 0.00 V, scan rate 10mV (only traces at E < - 0.20 V are shown). The insets illustrate the chain length dependence of the potentials of reductive desorption for the investigated organic adlayers. B Experimental i-t traces (dotted lines) of the reductive desorption recorded for freshly prepared monolayers of BP3 (A) after immersion at 0.0 V, stabilization, and subsequently stepping the potential from E = - 0.90 V (waiting time twait = 30 s) to various final potential Ef, which are indicated in the figure. The solid curves represent the numerical fits calculated according to the models represented by Eq. 3 [145]...

Historically, Frumldn-type models, which represent the Helmholtz region by a network of two or three condensers [449, 520-523] and classical thermodynamics based on a mean-field treatment [524-526], were apphed first to describe 2D phase transitions in organic adlayers at metal-electrolyte interfaces as a function of concentration, potential, and temperature (Sect. 33.2.2). In the simplest... 

Kinetic Aspects The kinetics of 2D phase formation and dissolution of organic adlayers were mostly studied by i—t, q —t or C-t single or multiple potential step experiments, and analyzed on the basis of macroscopic models according to strategies described in Chapter 3.3.3. Only rather recently, modern in situ techniques such as STM [20, 201, 453, 478, 479, 484, 487, 488] and time-resolved infrared spectroscopy (SEIRAS) [475,476] were applied to study structural aspects of these phase transitions at a molecular or atomistic level. 

Computational efforts to describe lateral interactions and compare the results with experiment in terms of isotherms started much earlier"" than the experimental information was well prepared. Qualitatively, these initial resirlts obtained in frames of lattice-gas model are interesting, as they demonstrate a possibihty of attractive H-H interactions in the case of coadsorption with repulsing anions. Modelling of mixed adlayers at various computational levels was systematically developed by Koper and coworkers, and now represents a rather general approach. It can be probably applied to mixed adlayers with short-range interactions of completely different type, earlier considered at phenomenological level (mixed ionic or organic" adlayers). 

Despite those prospects of practical applications, the details of structure and composition of the organic adlayer, which directly influence the quality of surface,... 

---