SAMs organosulfur

Organosulfur Adsorbates on Metal and Semiconductor Surfaces. Sulfur compounds (qv) and selenium compounds (qv) have a strong affinity for transition metal surfaces (206—211). The number of reported surface-active organosulfur compounds that form monolayers on gold includes di- -alkyl sulfide (212,213), di- -alkyl disulfides (108), thiophenols (214,215), mercaptopyridines (216), mercaptoanilines (217), thiophenes (217), cysteines (218,219), xanthates (220), thiocarbaminates (220), thiocarbamates (221), thioureas (222), mercaptoimidazoles (223—225), and alkaneselenoles (226) (Fig. 11). However, the most studied, and probably most understood, SAM is that of alkanethiolates on Au(lll) surfaces. 

Molecular self-assembly is a technique to form highly ordered, closely packed mono-layers on various substrates via a spontaneous chemisorption process at the interface.11,12 Earlier research done in this field includes the self-assembly of fatty acids monolayers on metal oxides,14,15 SAMs of organosilicon derivatives on metal and semiconductor oxides,16,17 and organosulfur SAMs on metal and semiconductor surfaces.18,19 Among the organosulfur SAMs, the most thoroughly investigated and characterized one is alkanethiol SAM formed on Au(l 11) surfaces.12... 

CHEMISTRY OF ORGANOSULFUR COMPOUNDS AT THE GOLD INTERFACE AND CHARACTERIZATION OF SAMs... 

With respect to the latter it was realized not long after the introduction of organosulfur SAMs that they represent ideal model systems to study interfacial... 

Tab. 1 Chemical systems of organosulfur compounds and substrates that form SAMs...

Microcontact Printing by Use of Organosulfur Inks Whitesides and coworkers have developed a set of techniques called soft lithography that offers tools for micropatteming that complement and extend the conventional fabrication methods [89, 330]. They emphasize that the ability to control surface properties using SAMs is most useful when combined with spatially defined patterns. Soft lithography allows the creation of useful... 

The original work of Nuzzo and Allara [4] on the use of the strong interaction between gold surfaces and organosulfur compounds for monolayer construction opened the field of SAMs prepared by molecular self-assembly on metal substrates via formation of metal-thiolate (or disulfide or dialkyl sulfide) bonds [15]. The introduction of functional SAMs on metal substrates was a natural development that followed [10, 11]. Owing to the similarity with highly specialized biological membranes, functional SAMs are sometimes called artificial membranes. 

Organosulfur-based SAMs Organosulfiir-based SAMs have been extensively studied and are well understood. These types of molecules have shown to self-assemble on a number of metal surfaces including Au, Ag, Cu, Pt, and Fe, " the preferred surface being clean and hydrophilic. Au is the most commonly used for such type of SAMs, as sulfur has a relative strong bond to Au. In addition, Au does not have a stable oxide, hence is easy to handle in... 

It is well known that organosulfur compounds react with gold surfaces. In 1982 Taniguchi et al. observed the spontaneous formation of pyridine disulfide SAMs on a gold surface [62]. In 1983, Nuzzo and Allara showed that SAMs of alkanethiolate on gold could be prepared by adsorption of n-alkyl disulfides from dilute solutions [63]. This report initiated a rapid growth in SAM research. 

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