Dynamic Structures of Host-Guest Systems

摘要: As illustrated elsewhere in this volume, calixarenes have proven to be a remarkably versatile class of materials. Numerous schemes been devised that employ the simple calixarenes, modified molecules, surface-bound species or larger assemblies for variety functions. With large amount information now available, it is quite appropriate assess our state knowledge, as ultimately rational design next generation materials depends on level understanding structural and dynamic details currently known species. In work we summarise studies contributed calixarenes. previous reviews noted difficulty even simplest has caused [1,2]: general, compounds are disordered, often with involvement both guest host sub-lattices there evidence coupling between them. We also advanced use synoptic approaches, where complementary techniques develop improved models. Without doubt, combination crystallography solid-state nuclear magnetic resonance (NMR) spectroscopy effective solving number complex problems, continuing progress technique development will advance these capabilities further. During course stayed ptert-butylcalix[4]arenes (tBC), starting very first tBC structure reported, toluene guest. This compound under study laboratory nearly ten years, shown some unusual effects, such superlattice diffraction peaks fade time wavelength-dependent structure. Also, good model was found refined well but turned out wrong symmetry by NMR spectroscopy. At start work, only few were tBCs, presumably because low solubility many solvents. Many commonly held views derive from limited database easily vast oversimplifications, e.g., suitability specific types general features host-guest complexes contributing factors stability. less conventional approaches able prepare Chapter 16