System synthesis present challenges

We begin our discussion of nanocrystals in this chapter with the most challenging problem faced in the field the preparation and characterization of nanocrystals. These systems present challenging problems for inorganic and analytical chemists alike, and the success of any nanocrystal synthesis plays a major role in the further quantitative study of nanocrystal properties. Next, we will address the imique size-dependent optical properties of both metal and semiconductor nanoeiystals. Indeed, it is the striking size-dependent colours of nanocrystals that first attracted... 

New natural polymers based on synthesis from renewable resources, improved recyclability based on retrosynthesis to reusable precursors, and molecular suicide switches to initiate biodegradation on demand are the exciting areas in polymer science. In the area of biomolecular materials, new materials for implants with improved durability and biocompatibility, light-harvesting materials based on biomimicry of photosynthetic systems, and biosensors for analysis and artificial enzymes for bioremediation will present the breakthrough opportunities. Finally, in the field of electronics and photonics, the new challenges are molecular switches, transistors, and other electronic components molecular photoad-dressable memory devices and ferroelectrics and ferromagnets based on nonmetals. 

Asymmetric synthesis refers to the conversion of an achiral starting material to a chiral product in a chiral environment. It is presently the most powerful and commonly used method for chiral molecule preparation. Thus far, most of the best asymmetric syntheses are catalyzed by enzymes, and the challenge before us today is to develop chemical systems as efficient as the enzymatic ones. 

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