Transition group elements

Dithiocarbamates of transition group elements in unusual oxidation states. J. Willemse, J. A. Cras, J. J, Steggerda and C. P. Keijzers, Struct. Bonding (Berlin), 1976, 28, 83-126 (195). 

It is then shown that (excepting the rare-earth ions) the magnetic moment of a non-linear molecule or complex ion is determined by the number of unpaired electrons, being equal to ms = 2 /S(S + 1), in which 5 is half that number. This makes it possible to determine from magnetic data which eigenfunctions are involved in bond formation, and so to decide between electron-pair bonds and ionic or ion-dipole bonds for various complexes. It is found that the transition-group elements almost without exception form electron-pair bonds with CN, ionic bonds with F, and ion-dipole bonds with H2O with other groups the bond type varies. 

Dithiocarbamates of Transition Group Elements in Unusual Oxidation States... 

Willemse, J., Cras, J.A., Steggerda, J.J., Keijzers, C.P. Dithiocarbamates of Transition Groups Elements in Unusual Oxidation State. Vol. 28, pp. 83-126... 

This mode of calculation has been called the EAN rule (effective atomic number rule). It is valid for arbitrary metal clusters (closo and others) if the number of electrons is sufficient to assign one electron pair for every M-M connecting line between adjacent atoms, and if the octet rule or the 18-electron rule is fulfilled for main group elements or for transition group elements, respectively. The number of bonds b calculated in this way is a limiting value the number of polyhedron edges in the cluster can be greater than or equal to b, but never smaller. If it is equal, the cluster is electron precise. 

There are three distinct areas of the periodic table—the main group elements, the transition group elements, and the inner transition group elements. We will focus our attention at first on the main group elements, whose properties are easiest to learn and to understand. 

Since the discovery of the phenomenon of paramagnetic resonance absorption by Zavoisky 19) in 1945, this method has been extensively applied to the study of the properties of unpaired electrons in various substances. A large amount of information has been obtained concerning the transition group elements in various valence states and is summarized in review articles 20) generally these elements have been studied in dilute concentration in a diamagnetic host crystal of known structure. 

Catalytic agents Mainly metals and metal oxides are used as the catalytically active components that are dispersed onto the support. The transition group elements and subgroup I are used extensively in environmental applications. Ag, Cu, Fe, Ni, their oxides, and precious metals like Pt, Pd, and Rh are a common choice in catalysis. 

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