Assembling chemical structures, problems

PROBLEMS ASSOCIATED WITH ASSEMBLING CHEMICAL STRUCTURES... 

New models and ideas can be tested by computers to see how they compare with experimental results. Furthermore, calculations can be done using models, applying them to new aspects of the problem. Model-based methods have been applied in various ways to many current problems—drug design, protein folding, the struaure and funaion of biological molecular and molecular assemblies, and the effect of solution on chemical structures and... 

Manufacturing Improvements for precision engineering new processes, and tools to manipulate matter at the atomic level nanopowders that are sintered into bulk materials with special properties that may include sensors to detect incipient failures and actuators to repair problems chemical-mechanical polishing with nanoparticles, self-assembling of structures from molecules bioinspired materials and biostructures... 

DNA self-assembly could be used in a variety of ways to solve this problem molecular components (e.g., AND, OR, and NOT gates, crossbars, routing elements) could be chemically attached to DNA tiles at specific chemical moieties, and subsequent self-assembly would proceed to place the tiles (and hence circuit elements) into the appropriate locations. Alternatively, DNA tiles with attachment moieties could self-assemble into the desired pattern, and subsequent chemical processing would create functional devices at the positions specified by the DNA tiles. None of these approaches has yet been convincingly demonstrated, but it is plausible that any of them could eventually succeed to produce two- or three-dimensional circuits with nanometer resolution and precise control of chemical structure. 

As this volume attests, a wide range of chemistry occurs at interfacial boundaries. Examples range from biological and medicinal interfacial problems, such as the chemistry of anesthesia, to solar energy conversion and electrode processes in batteries, to industrial-scale separations of metal ores across interfaces, to investigations into self-assembled monolayers and Langmuir-Blodgett films for nanoelectronics and nonlinear optical materials. These problems are based not only on structure and composition of the interface but also on kinetic processes that occur at interfaces. As such, there is considerable motivation to explore chemical dynamics at interfaces. 

Nature uses the transition-metal elements iron and nickel, rather than noble metals, and in their ionic form rather than the metals. As will be seen in this book, for the simplest chemical reaction, the metal-ion centres in hydrogenases are some of the most complex catalysts known. Their structures, which have just been elucidated, have proved to be an elegant and totally unexpected solution to the problem. The construction of these catalysts is in itself a molecular assembly line of extraordinary sophistication. 

---