Self-assembled monolayers energy transfer

Figure 5.2 Tafel plots of In k versus overpotential for a mixed self-assembled monolayer containing HS(CH2)i600C-ferrocene and HS(CH2)isCH3 in 1.0 M HCIO4 at three different temperatures V, 1 °C O/ 25 °C , 47°C. The solid lines are the predictions of the Marcus theory for a standard heterogeneous electron transfer rate constant of 1.25 s-1 at 25 °C, and a reorganization energy of 0.85 eV (= 54.8 kj moh1). Reprinted with permission from C. E. D Chidsey, Free energy and temperature dependence of electron transfer at the metal-electrolyte interface, Science, 251, 919-922 (1991). Copyright (1991) American Association for the Advancement of Science...

Imahori et al. reported on the energy transfer in mixed self-assembled monolayers of pyrene and porphyrin [83]. The molecular structures of the disulfide-terminated chromophores are illustrated in Figure 5.53. Porphyrin and pyrene dimers were coadsorbed onto Au(lll) mica substrates in different ratios. The ratios of pyrene to porphyrin were experimentally determined from absorption spectroscopy and the pyrene dimer was observed to adsorb preferentially, possibly due to its strong... 

Chrisstoffels, L. A. J. Adronov, A. Frechet, J. M. J. Surface-Confined Light Harvesting, Energy Transfer, and Amplification of Fluorescence Emission in Chromophore-Labeled Self-Assembled Monolayers. Angew. Chem. Int. Ed. 2000, 39, 2163-2167... 

The molecular ion (M — H) intensity of the methyl-terminated phosphate is 1 order of magnitude greater than that of the hydroxy-terminated phosphate. It has been reported that the detection of molecular mass ions M - H is correlated with the degree of order in self-assembled monolayers, resulting from energy transfer and stability effects. We assume that the higher count rate... 

Self-assembled and spontaneously adsorbed monolayers offer a facile means of controlling the chemical composition and physical structure of a surface. As discussed later in Chapter 5, applications of these monolayers include modeling election transfer reactions, biomimetic membranes, nano-scale photonic devices, solar energy conversion, catalysis, chemical sensing and nano-scale lithography. 

In Section 3.1.4 we described Kuhn s early studies of energy transfer in monolayers. Their experiments are very well-known. They laid the basis for a rapidly expending area of photophysics concerned with the study of molecular assemblies such as LB-films, various monolayers, and vapor-deposited films. These photophysical techniques will become particularly important in elucidating the molecular organization in self-assembled systems. 

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