Physisorbed organic molecule

Cyr D M, Venkataraman B and Flynn G W 1996 STM investigations of organic molecules physisorbed at the liquid-solid interface Chem. Mater. 8 1600... 

Small organic molecules have been the subject of most surface-structure studies of molecular adsorbates. Most of these molecules are alkenes (such as ethylene) and aromatic molecules (such as benzene and substituted benzenes). Saturated hydrocarbons physisorb only at low temperatures and although some ordered surface structures have been obtained using graphite as a substrate, these structures exhibit van der Waals packing without forming stronger chemical bonds. 

The understanding of the relationships between molecular structure of tailored organic molecules, their hierarchical organization in assemblies chemically bound to surfaces and interfaces as well as their fimctionality represent fundamental topics of current interest [104,105]. hi the following we shall focus on so-called chemisorbed, self-assembled monolayers (SAM), which are distinctly different from the physisorbed, hydrogen-bonded adlayers discussed in the previous paragraph. Following a historical development we will use the terminus self-assembled monolayers herein exclusively as molecular assemblies formed by chemisorption of an active surfactant onto a solid surface [106-108]. We will specifically focus on selected results with aromatic SAMs on Au(lll) electrodes at solid-liquid interfaces. 

SAMs on solid substrates discussed in this chapter fall into the latter category most of the SAM-modified substrates are prepared by exploiting either the strong interaction between sulfur-bearing organic molecules and metal surfaces [4] or the covalent siloxane bonds [5], The effect of metal-ion coordination in such chemisorbed layers, unlike that in the case of solution chemistry or physisorbed systems, is in influencing the local order in the SAM, while in most cases... 

Finally, the substitution of Pt by BDD leads to a dramatic enhancement of the oxidation ability of the Fenton-based EAOPs, as observed for the pesticide 2,4-dichlorophenoxyacetic acid in Fig. 2. At present, BDD is the best anode material to oxidize organic pollutants, since it yields a high concentration of physisorbed hydroxyl radicals (BDD( OH)) at a very positive anode potential from reaction (7). Therefore, in the EF with BDD, the refractory organic molecules and their complexes with metal ions can be oxidized by the combined action of BDD( OH) formed at the anode and OH produced in the bulk. 

In this chapter, when reporting on copper nanomaterials, we will implicitly focus on the nanostructure main part-the core. The existence of a relatively thin stabilizing shell (composed of organic stabilizers, copper oxide or hydroxide, chemi- or physisorbed solvent molecules, etc.) surrounding the NP core will be accepted as a natural consequence of both the size and the chemical reactivity of the copper phase. 

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