Orbital magnetic properties

In each Cp, there are five p orbitals and as shown for structure 2.43, in the most common rf-mode of bonding, they all are used. The energies of the five highest occupied molecular orbitals (HOMOs) of Cp M complexes are very close to each other. Based on the electron occupancy of these orbitals, magnetic properties and variation in the distances of the centers of the Cp rings from the metal atoms can be easily explained. 

In his valence bond theory (VB), L. Pauling extended the idea of electron-pair donation by considering the orbitals of the metal which would be needed to accommodate them, and the stereochemical consequences of their hybridization (1931-3). He was thereby able to account for much that was known in the 1930s about the stereochemistry and kinetic behaviour of complexes, and demonstrated the diagnostic value of measuring their magnetic properties. Unfortunately the theory offers no satisfactory explanation of spectroscopic properties and so was... 

The magnitude of the separation between the adjacent states of a term indicates the strength of the spin-orbit coupling, and in all but two cases (Sm and Eu ) it is sufficient to render the first excited state of the Ln ions thermally inaccessible, and so the magnetic properties are determined solely by the ground state. It can be shown that the magnetic moment expected for such a situation is given by ... 

The molecular orbitals are arranged in order of increasing energy. The relative energies of these orbitals are ordinarily deduced from experiment Spectra and magnetic properties of molecules are used. 

The magnetic properties of Pu compounds in different oxidation states are reviewed. New measurements on Pu(C8H8)2, PuFi, [(C2Hs)itN]2PuCl6, and [ (C2H5)itN]itPu(NCS)s are presented. The interpretation of the data is based on intermediate, j-j mixed crystal field states and orbital reduction due to covalency. Especially in the case of the organometallic compounds a large orbital reduction is found. 

Orbital reduction, covalency, and magnetic properties of organo-metallic and coordination... 

As we can see, the diffuse orbitals play a dramatic part in the description of the magnetic properties of BeH not less two sets of these orbitals (basis set III) are necessary to obtain an accurate and converging value of the susceptibility. The BeH-anion should be diamagnetic and its mean susceptibility is of the order of -2.10- erg.G-2.mol"L Note that the use of a single set of supplementary diffuse orbitals is not sufficient to bring to light this magnetic property. 

On the other hand, the XPS data near the Fermi level provide us the valuable information about the band structures of nanoparticles. XPS spectra near the Fermi level of the PVP-protected Pd nanoparticles, Pd-core/ Ni-shell (Ni/Pd = 15/561, 38/561) bimetallic nanoparticles, and bulk Ni powder were investigated by Teranishi et al. [126]. The XPS spectra of the nanoparticles become close to the spectral profile of bulk Ni, as the amount of the deposited Ni increases. The change of the XPS spectrum near the Fermi level, i.e., the density of states, may be related to the variation of the band or molecular orbit structure. Therefore, the band structures of the Pd/Ni nanoparticles at Ni/Pd >38/561 are close to that of the bulk Ni, which greatly influence the magnetic property of the Pd/Ni nanoparticles. 

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