Core electrons octahedral complexes

Sometimes, the physicochemical properties of ionic species solubilized in the aqueous core of reversed micelles are different from those in bulk water. Changes in the electronic absorption spectra of ionic species (1 , Co ", Cu " ) entrapped in AOT-reversed micelles have been observed, attributed to changes in the amount of water available for solvation [2,92,134], In particular, it has been observed that at low water concentrations cobalt ions are solubihzed in the micellar core as a tetrahedral complex, whereas with increasing water concentration there is a gradual conversion to an octahedral complex [135],... 

Dahl (175). The basic structure is defined by an octahedral core with trans-tellurium atoms and is isoelectronic with the ruthenium complex 183. Both clusters may also be compared with the ruthenium and osmium bismuth complexes, 125 and 129, which, although octahedral, contain two less electrons. A complex containing an additional carbonyl group, viz. [Te2Co4(CO)u], 185, has been described by Rauchfuss (172) as resulting from the reaction... 

The electronic configuration of elemental iron is ls 2s p 3s 3p 3d 4s or shortened to include the argon core as [Ar]3d 4s. Ferrous and ferric cations contain two and three fewer electrons, respectively, in the 4s and 3d orbitals. The molecular orbital theory of octahedral complexes dictates that iron can utilize up to nine orbitals (one s, three p, and five d) to form molecular orbitals resulting in iron-ligand bonds [1]. 

The structural relationship between the molecular and solid-state compounds has been a hot issue in inorganic chemistry for some time (25-27). The extrusion (or excision) from preformed solid-state cluster compounds is one of the major synthetic methods of the preparation of cluster complexes (26). Use of cluster complexes as precursors to solid-state cluster compounds is the reverse reaction of excision. Both reactions utilize the structural similarity of the metal cluster units. The basic cluster units of polyhedra (deltahedra) or raft structures are triangles, and both molecular and solid-state clusters with octahedral, tetrahedral, and rhomboidal cores have been reported. Similarity of other properties such as electronic structures based on the cluster units is also important. The present review is concerned with the syntheses and structures of the cluster complexes of the group 6 metals and with their relationships to solid-state chemistry. 

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