Chemisorbed Self-Assembled Monolayers

O. AZZARONI; R.C. SALVAREZZA

Supramolecular Chemistry: from molecules to nanomaterials

John Wiley & Sons, Ltd.

Lugar: Chichester; Año: 2012; p. 3445 - 3462

Since the second half of the twentieth century, the preparation and characterization of self-assembled molecular films on solid surfaces have attracted very great and widespread interest, both as a fundamental intellectual and technological challenge to chemists, physicists, and materialsscientists. The very possibility of designing and creating surfaces from scratch marks a profound departure from traditional surface science. One major attraction of surface-confined molecular assemblies is its potential to combine and manipulate topological, chemical, and functionalfeatures that are essential for a wide variety of technological applications such as microanalysis, biotechnology, nanofabrication, or corrosion protection, just to name a few examples.As we move further into the new century, self-assembled thin films seem indeed to offer almost unlimited opportunities for fundamental and applied surface science. At present, self-assembled monolayers (SAMs) constituted of chemisorbed species represent fundamental building blocks for creating complex structures by the so-called "bottom-up approach". The self-assembly of molecules into structurally organized thin films exploiting the flexibility of organicand supramolecular chemistry has led to the generationsynthetic surfaces with well-defined chemical and physical properties. Chemical synthesis offers the appeal of an unparalleled level of control over the selection of functional features while hydrophobic and van der Waals interactions lead to the spontaneous association of the predesigned building blocks into stable, well-defined surface structures. In this work, we first sketch the fundamental aspects of chemisorbed SAMs as a tool for building complex molecular systems. Using thiol SAMs as model systems, we first briefly review the self-assembly, surface structure, and stability under different experimental conditions. We also point out the characteristics of SAMs that make them suitable especially for building active micro- and nanostructured molecular systems on surfaces, and stress their limitations resulting from defects, contaminants, and disorders. Finally, we present examples of interfacial architectures drawn from supramolecular and covalent systems to illustrate the potential of SAMs as robust platforms for functional 3D structures on solid substrates.