Magnetic Properties of Electron and Nuclear Spins

This chapter is intended to recall the principles of magnetism, the definition of magnetic induction and of magnetic induction in a vacuum which is referred to as magnetic field. Readers may not recollect that the molar magnetic susceptibility is expressed in cubic meters per mol Some properties of electron and nuclear spins are reviewed and finally some basic concepts of the magnetic resonance experiments are refreshed. In summary, this chapter should introduce the readers into the language used by the authors. 

In spite of the great number of measurements of the properties of this compound, including conductivity, dielectric constant, magnetic susceptibility, electron and nuclear spin resonance, specific heat, thermoelectric power, etc., many over wide temperature and frequency ranges, there is still no consensus as to how all the various pieces of the puzzle fit together. Even such a basic question as to whether most of the high temperature conduction is along the TTF or the TCNQ stacks or in hybridized orbitals of both remains open. 

Electron and nuclear magnetic moments can be regarded as arising from a property of the particles, i.e. that they possess an intrinsic angular momentum as if they were spinning. Such angular momenta are given by... 

The first term is the Zeeman interaction depending upon the g(RS OW, q ) tensor, external magnetic field B0 and electron spin momentum operator S the second term is the hyperfine interaction of the th nucleus and the unpaired electron, defined in terms hyperfine tensor A (Rsklw, qj) and nuclear spin momentum operator n. The following terms do not affect directly the magnetic properties and account for probe-solvent [tfprobe—solvent (Rsiow, qJ)l ld solvent-solvent //solvent ( qj)] interactions. An explicit... 

Spectroscopic Properties of Inorganic and Organometallic Compounds, ed. N. N. Greenwood, vols. 1 (1968), 2 (1969), 3 (1970). Each volume surveys the literature of the year before publication, under seven main chapter headings Nuclear magnetic resonance spectroscopy Nuclear quadrupole resonance spectra Electron spin resonance spectroscopy Microwave spectroscopy Vibrational spectra Electronic spectra and Mossbauer spectroscopy. 

Electron Spin Resonance General and Synthetic Methods Mass Spectrometry Nuclear Magnetic Resonance Organometallic Chemistry Organophosphorus Chemistry Photochemistry Spectroscopic Properties of Inorganic and Organometallic Compounds... 

The nuclear spin-spin coupling constant, "/(A-B) is a measure of the energy of interaction between the magnetic moments of nuclei A and B. The interaction is transmitted by a magnetic polarization of the electrons in the molecule and J is therefore an intrinsic second-order property of the molecule, depending in a subtle manner on the details of the electron distribution. It is often convenient to define a reduced spin-spin coupling constant, "K(A-B), independent of the magnetic moments of A and B... 

Abstract This tribute to the work by Carl Johan Ballhausen focuses on the emergence of quantitative means for the study of the electronic properties of complexes and molecules. Development, refinement, and application of the orbital picture elucidated electric and magnetic features of ranges of molecules when used for the interpretation of electronic transitions, electron spin resonance parameters, rotatory dispersion, nuclear quadrupole couplings as well as geometric bonding patterns. Ballhausen s profound impact on the field cannot be overestimated. 

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