Other topics in one-dimensional

Nuclear Magnetic Resonance Spectroscopy Part Four Other Topics in One-Dimensional NMR... 

Chapter 5 described the important details of dynamic (nonsteady-state) zone formation in one-dimensional systems. Omitted were other important aspects of zone formation and structure, including steady-state zones, two-dimensional zones, and the problem of statistical zone overlap. These topics will be examined in this chapter. 

The confluence of theory and experiment achieved in recent years has greatly deepened our understanding of molecular photodissociation. At this point, however, it is important to underline that the cornerstone of realistic dynamical investigations is a multi-dimensional potential energy surface (PES). The interrelation between PESs on one hand and the various dissociation cross sections on the other hand is one prominent topic of this book and therefore we think it is useful to elucidate some qualitative aspects of PESs before we start with the development of the dynamical concepts. 

In Chapter 11, Molecular Electron Transfer, the broad and deep field of electron-transfer reactions of metal complexes is surveyed and analyzed. In Chapter 12, Electron Transfer From the Molecular to the Nanoscale, the new issues arising for electron-transfer processes on the nanoscale are addressed this chapter is less a review than a toolbox for approaching and analyzing new situations. In Chapter 13, Magnetism From the Molecular to the Nanoscale, the mechanisms and consequences of magnetic coupling in zero- and one-dimensional systems comprised of transition-metal complexes is surveyed. Related to the topics covered in this volume are a number addressed in other volumes. The techniques used to make the measurements are covered in Section I of Volume 2. Theoretical models, computational methods, and software are found in Volume 2, Sections II and III, while a number of the case studies presented in Section IV are pertinent to the articles in this chapter. Photochemical applications of metal complexes are considered in Volume 9, Chapters 11-16, 21 and 22. 

Carbon nanotubes (CNTs) are unique one-dimensional (1-D) nanomaterials composed entirely of sp hybridized carbon atoms. Unlike other 1-D nanomaterials, every atom in a CNT is located on the surface, which gives rise to unique properties desirable for many applications. In order to utilize this nanomaterial in most applications, CNTs must be chemically functionalized. Covalent functionalization of CNTs represents a vibrant field of research. Often in covalent modification, the sidewalls or the end groups are subject to functionalization (Figure 1) the primary problem with this approach, however, is that the physical properties of the nanotube are impaired. As this chapter does not cover this topic, interested readers are referred to high-quality review articles. In order to chemically functionalize CNTs while preserving their physical properties, supramolecniar chemistry of CNTs needs to be developed. 

Formation of one-dimensional channels with no rotation was observed in the complexes between per-ethylated pillar[5]arene 6.3 and l,4-his(imidazol-l-yl)butane (Figure 6.13d). The assembly of host-guest complexes of 5-bromovaleronitrile and a non-symmetrical pillar[5]arene with five methyls on one side and five n-pentyls on the other (6.22) also formed onedimensional channels (Figure 6.13e). The application incorporating the alignment of these guest molecules in the one-dimensional channels constructed from pillar[5]arenes is a topic for future investigation. 

Chapters 1-5 cover the basic physics and optical properties of liquid crystals intended for beginning workers in liquid crystal related areas. Although the major focus is on nematics, we have included sufficient discussions on other mesophases of liquid crystals such as the smectics, ferroelectrics, and cholesterics to enable the readers to proceed to more advanced or specialized topics elsewhere. New sections have also been added. For example, in Chapter 4, a particularly important addition is a quantitative discussion of the optical properties and fundamentals of one-dimensional photonic crystal band stractures. Dispersion is added to fill in an important gap in most treatments of cholesteric liqrrid crystals. 

By this time, you are probably experienced in working with units. Most science and engineering texts have a section in the first chapter on this topic. In this text, we will mainly use the Systeme International, or SI units. The SI unit system uses the primary dimensions m, s, kg, mol, and K. Details of different unit systems can be found in Appendix D. One of the easiest ways to tell that an equation is wrong is that the units on one side do not match the units on the other side. Probably the most common errors in solving problems result from dimensional inconsistencies. The upshot is Pay close attention to units Try not to write a number down without the associated units. You should be able to convert between unit systems. It is often easiest to put all variables into the same unit system before solving a problem. 

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