Magnetism of coordination compounds

Although CFT can explain the magnetism of coordination compounds and predict that they are colored, it is not a quantitative theory. It cannot predict, for instance, the exact color of a transition metal complex because there is no way of rationalizing the relative magnitude of a priori. Even for a metal ion having... 

Vlek, Antonin A., Polarographic Behavior of Coordination Compounds. Vrieze, K. and van Leeuwen, P. W. N. M., Studies of Dynamic Organometallic Compounds of the Transition Metals by Means of Nuclear Magnetic 5 211... 

Ciofini, I. and Daul, C. A. 2003. DFT Calculations of Molecular Magnetic Properties of Coordination Compounds , Coord. Chem. Rev.. 238, 187. 

Due to some special structural and magnetic peculiarities, in particular, free-radical properties, the quinone ligands and their metal complexes are apart from the other kinds of coordination compounds [125a, 138a], as will be shown below. Here we present an overview of the main methods for the synthesis of complexes containing benzoquinone, semiquinone, and catecholate ligands, and peculiarities of the products. 

Electronic Structure and Magnetism of Inorganic Compounds, ed. P. Day, vol. 1 (1972) covers ESR, electronic spectra and magnetic properties of ionic solids and coordination compounds, some parts of which were covered by early volumes of B6.1. 

J. F. Nixon and A. Pidcock Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy of Coordination Compounds, pp. 345-422 (111). 

Use crystal field theory to interpret the magnetic properties of coordination compounds in terms of the electron configurations of their central ions (Section 8.4, Problems 21-25). 

Magnetic Studies of Coordination Compounds Factors Affecting the Nature of Bonds Between Nickel and Certain Non-Metallic Atoms. 

Magnetic Studies of Coordination Compounds Square Coordinated Cobalt Compounds. 

Our purpose is not to focus on the methods of mass spectrometry but rather to provide illustrations of some of the types of situations that may occur when this technique is used to characterize organometallic compounds. A brief but useful description of some of the techniques used in the mass spectrometry of coordination compounds, including organometallic compounds, is available.54 Because mass spectrometry relies on the interaction of ions rather than neutral molecules with magnetic fields, the selection of ionizing techniques is an important consideration. Some of the most common ionizing techniques are listed in Table 6-8. 

Bonding theories for coordination compounds should be able to account for structural features, colors, and magnetic properties. The earliest accepted theory was the valence bond theory (Chapter 8). It can account for structural and magnetic properties, but it offers no explanation for the wide range of colors of coordination compounds. The crystal field theory gives satisfactory explanations of color as well as of structure and magnetic properties for many coordination compounds. We will therefore discuss only this more successful theory in the remainder of this chapter. 

The coordination chemistry involves the oxidation states from -i-7 to -1. Coordination numbers from 4 to 9 are known. Crystal field considerations and magnetic susceptibility measurements show that technetium forms low-spin compounds. Dinuclcar complexes frequently display metal to metal bond character. There is some evidence that technetium complexes are thermodynamically less stable and kinctically more reactive than the corresponding complexes of rhenium. A multitude of coordination compounds of technetium has been synthesized and unambiguously characterized. Investigations of the complex chemistry have been enormously stimulated by the development of Tc radiopharmaccuticals. 

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