Octahedral coordination electronic configurations

J. Sato, H. Kobayashi, Y. Inoue, Photocatalytic activity for water decomposition of indates with octahedrally coordinated d10 configuration. II. Roles of geometric and electronic structures, J. Phys. Chem. B 107 (2003) 7970-7975. 

The most common oxidation states and the corresponding electronic configuration of mthenium are +2 and +3 (t5 ). Compounds are usually octahedral. Compounds in oxidations states from —2 and 0 (t5 ) to +8 have various coordination geometries. Important appHcations of mthenium compounds include oxidation of organic compounds and use in dimensionally stable anodes (DSA). 

The most common oxidation states and the corresponding electronic configurations of osmium ate +2 and + (t5 ), which ate usually octahedral. Stable oxidation states that have various coordination geometries include —2 and 0 to +8 (P] The single most important appHcation is OsO oxidation of olefins to diols. Enantioselective oxidations have also been demonstrated. 

The most common oxidatiou states and corresponding electronic configurations of rhodium are +1 which is usually square planar although some five coordinate complexes are known, and +3 (t7 ) which is usually octahedral. Dimeric rhodium carboxylates are +2 (t/) complexes. Compounds iu oxidatiou states —1 to +6 (t5 ) exist. Significant iudustrial appHcatious iuclude rhodium-catalyzed carbouylatiou of methanol to acetic acid and acetic anhydride, and hydroformylation of propene to -butyraldehyde. Enantioselective catalytic reduction has also been demonstrated. 

The most common oxidation states, corresponding electronic configurations, and coordination geometries of iridium are +1 (t5 ) usually square plane although some five-coordinate complexes are known, and +3 (t7 ) and +4 (t5 ), both octahedral. Compounds ia every oxidation state between —1 and +6 (<5 ) are known. Iridium compounds are used primarily to model more active rhodium catalysts. 

The most common oxidation states and corresponding electronic configurations of platiaum are +2 which is square planar, and +4 which is octahedral. Compounds in oxidation states between 0 and +6 [t) exist. Platiaum hydrosilation catalysts are used in the manufacture of siHcone polymers. Several platiaum coordination compounds are important chemotherapeutic agents used for the treatment of cancer. 

The chemistry of Cr(III) in aqueous solution is coordination chemistry (see Coordination compounds). It is dominated by the formation of kineticaHy inert, octahedral complexes. The bonding can be described by Ss]] hybridization, and HteraHy thousands of complexes have been prepared. The kinetic inertness results from the electronic configuration of the Cr ion (41). This type of orbital charge distribution makes ligand displacement and... 

First, consider an octahedral nickel(ii) complex. The strong-field ground configuration is 2g g- The repulsive interaction between the filled 2g subshell and the six octahedrally disposed bonds is cubically isotropic. That is to say, interactions between the t2g electrons and the bonding electrons are the same with respect to x, y and z directions. The same is true of the interactions between the six ligands and the exactly half-full gg subset. So, while the d electrons in octahedrally coordinated nickel(ii) complexes will repel all bonding electrons, no differentiation between bonds is to be expected. Octahedral d coordination, per se, is stable in this regard. 

Octahedrally coordinated transition ions with odd numbers of 3d electrons in the destabilized Cg orbitals (i.e., d, <7 , and low-spin d configurations) are subject... 

The elements with such an electronic configuration known as luminescent centers are Cr, Mn and They are capable of substituting in a wide variety of metal oxide host systems. They are invariably oxygen-coordinated with six nearest neighbors, and may be in a pure octahedral or a distorted octahedral symmetry site. These luminescent centers exists in a d configuration (Fig. 5.23), and the electronic repulsion, which results from placing three electrons in the same set of d-orbitals yields several states identified as free... 

In other instances, irradiation of the d-d transition leads to no observable reaction. Examples of this behavior are found for complexes having a variety of d electron configurations and coordinative geometries square planar Ni(II) (3d)3 in Ni(CN)42 124 and mww-Ni(gIy)2 124 square planar Pd(II) in Pd(CN)42-,124 and tra -Pd(gly)2 square planar Pt(II) in Pt(CN)42" (5d)3 124 octahedral Co(III) (3d)6 in a variety of complexes (cf. Sect. III-C and III-D). A striking example of this type of behavior is afforded by the nonreversible photoisomerization of cis-Pt(gly)2 (5d)8 to trans-Pt(g y)2 [reaction (2)].124 It has been proposed that irradiation of either of these square planar complexes leads to the same tetrahedral intermediate which decays exclusively to mwj-Pt(gly)2. This behavior may be contrasted with the reversible photoisomerization shown in reaction (3).3... 

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