Molecular magnets solid-state

Perhaps the common characteristic of all contributions to this volume is the permanent concern about the intimate relationships between the structural and electronic properties. Indeed, the careful design of increasingly complex molecular and supramolecular architectures allows us now to anticipate many molecular and solid state properties, but the final solid state structures are always the results of many competing interactions. The resulting electronic properties of these radical assemblies, whether conductivity or magnetism, are always very sensitive to minute modifications of their solid state structures and one of the main difficulties through... 

The chemical shift is generally a sensitive function of the type of chemical environment around a nucleus. The magnitude of the shift is relatively small for protons, due to the fact that only one or two electrons surround the proton in chemical compounds. However, for heavier elements such as fluorine, it becomes quite large the F magnetic resonance of HF and Fj being separated by about 6 gauss at 10,000 gauss applied field. The chemical shift is a useful parameter in the study of molecular and solid state structure. 

Various spectroscopic techniques of atomic, molecular and solid-state physics are employed in order to obtain experimental NQCC values such as atomic and molecular beam magnetic resonance, optical and rotational spectroscopy, nuclear quadrupol resonance (NQR) in solids or nuclear magnetic resonance (NMR). Atoms containing /u or tt mesons... 

P. Garcia-Fernandez and 1. B. Bersuker, Class of molecular and solid state systems with correlated magnetic and dielectric bistabilities induced by the pseudo Jahn-Teller effect, Phys. Rev. Lett. 106, 246406 (2011). 

Magnetic resonance techniques, EPR (ESR) and NMR, can be used [341,342] to obtain information about atomic, ionic, molecular and crystallographic states before, during and after solid state reactions. Only a very restricted use has been made of the NMR of solids [342—345]. 

These limitations, most urgently felt in solid state theory, have stimulated the search for alternative approaches to the many-body problem of an interacting electron system as found in solids, surfaces, interfaces, and molecular systems. Today, local density functional (LDF) theory (3-4) and its generalization to spin polarized systems (5-6) are known to provide accurate descriptions of the electronic and magnetic structures as well as other ground state properties such as bond distances and force constants in bulk solids and surfaces. 

NMR spectroscopy is a powerful technique to study molecular structure, order, and dynamics. Because of the anisotropy of the interactions of nuclear spins with each other and with their environment via dipolar, chemical shift, and quadrupolar interactions, the NMR frequencies depend on the orientation of a given molecular unit relative to the external magnetic field. NMR spectroscopy is thus quite valuable to characterize partially oriented systems. Solid-state NMR... 

Nuclear magnetic resonance provides means to study molecular dynamics in every state of matter. When going from solid state over liquids to gases, besides mole- cular reorientations, translational diffusion occurs as well. CD4 molecule inserted into a zeolite supercage provides a new specific model system for studies of rotational and translational dynamics by deuteron NMR. 

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