Octahedral metals

Solid-state cluster chemistry is dominated by octahedral (M 5L8)L6 and (MsLi2)L units which are the focus of this paper. These two cluster types are different in the way the metal octahedral core is surrounded by the ligands. In (MsLg)L6-type clusters (Fig. 6.1a), typical for molybdenum and rhenium halides, chalcogenides, and chalcohalides, eight innei hgands (L ) cap the octahedron faces and six outer ligands (L ) are located in the apical positions [9]. For metals with a smaller number of valence electrons, the (M6L i2)L -type clusters... 

Although the model has been extended to other types of coordination compounds [83, 84], namely d metal octahedral complexes such as [MCl6- (NCMe) ] +" (M = Nb, Ta n = 0-2) [84], its application still remains little explored [82-84]. 

As this takes place, hydrogen atoms can occupy quite definite positions in the lattice of metal (octahedral, tetrahedral, or both octa- and tetrahedral interstitial sites). 

Not only can existing structural motifs be modified by cluster substitution but completely new materials can be synthesized. (Zhou et al., 2004) employed an early transition-metal octahedral cluster with terminal cyano ligands, [Nb6Cli2(CN)6]4-(Figure 8.6, see also Section 3.3.5) in combination with a metal linker complex... 

Figure 12. LEFT a unit cell of the monoclinic 1 384 showing the insulating RhSg backbone (essentially the 1 283 phase) with the metallic octahedral Rhe eaves to either side. TOP RIGHT FEFF models of the Rhe octahedra with varying geometries of adsorbed 0(H) center) clean cluster, a) 1-fold O, b) axial 2-fold O, c) equatorial 2-fold O, d) 3-fold O. BOTTOM RIGHT The theoretical Ap signatures generated by EEEE8 from the above models.

Assume that the spin-only formula is valid (first row metal, octahedral complex) ... 

Uncoordinated metal Octahedral complex Ligand sigma orbitals... 

The group 6 metal octahedral hexacarbonyls have PE spectra where the < -band, resulting from ionization of the tzg configuration, is well separated from ionizations that arise principally from ligand orbitals (Figure... 

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