Regular octahedral

This is the point group to which all regular octahedral molecules, such as SFe (Figure 4.12b) and [Fe(CN)6], belong. 

All regular fefrahedral molecules, which belong to fhe poinf group (Section 4.2.8), may show such a rofational spectrum. However, those spherical rotors that are regular octahedral molecules and that belong to the Of, point group (Section 4.2.9) do not show any such... 

Polyatomic molecules cover such a wide range of different types that it is not possible here to discuss the MOs and electron configurations of more than a very few. The molecules that we shall discuss are those of the general type AFI2, where A is a first-row element, formaldehyde (FI2CO), benzene and some regular octahedral transition metal complexes. 

Figure 7.38 Splitting of d orbitals in a regular octahedral field...

All the forbidden electronic transitions of regular octahedral transition metal complexes, mentioned in Section 7.3.1.4, are induced by non-totally symmetric vibrations. 

Ooso (structure I) has a regular octahedral cluster of 6 B atoms surrounded by a larger octahedron of 6 radially... 

The regular octahedral structure of SFg and the related structure of S2F]q (Fig. 15.20) call for little comment except to note the staggered (D4d) arrangement of the two sets of Feq in S2F10 and the unusually long S-S distance, both features presumably reflecting interatomic repulsion between the F atoms. SFg is also of... 

Indeed, in. some cases it is probable that V2 is not ob.served at all, but that the fine. structure arises from term splitting due to spin-orbit coupling or to distortions from regular octahedral symmetry. 

They contain octahedral MF (Table 1.3) [33] in XeF+RuF the attraction of XeF+ distorts the octahedron by pulling one fluorine towards it, so that there is one long Ru-F distance of 1.919 A compared with the others of 1.778-1.835 A (EXAFS measurements indicate KRuF6 has regular octahedral coordination (Ru-F 1.845 A)) [19]. 

The crystal structure of the K(18-crown-6) salt shows a fac-octahedral structure (Ru—H 1.59-1.71 A, Ru—P 2.312-2.331 A) with a large distortion from regular octahedral geometry (H-Ru-H 70-88° P-Ru-P 102-111°) owing to the disparate steric demands of the hydride and tertiary phosphine ligands [95]. 

All six terminal atoms are equivalent in a regular octahedral molecule. 

Attempts to prepare related hpp complexes of tantalum were only partially successful. Reaction of 2 equivalents of either (hpplSiMes or in situ generated Li[hpp] with Tads afforded a solid that analyzed correctly for the compound (hpp)2TaCl3. X-ray structural analysis of the crystallized product identified the coordination isomer [Ta(hpp)4][TaCl6], with a distorted dodecahedral cation and a regular octahedral anion (Figure 28). °... 

The success and the failure in locating the regular octahedral geometries as energy minima at the UB3LYP/6-31 + G(d) levels are denoted by the plus (+) and minus (-) signs, respectively... 

The ligand properties of a cyclic dithioether, 1,4-dithiane monosulphoxide (DTMSO), have been studied by physical measurements . The infrared spectra indicate that the metal cation coordinates to the oxygen lone pair electrons of DTMSO. Both infrared and ligand-field spectra show the presence of octahedral ions MfDTMSO) in the compounds M(DTMS0)g(C104) and M(DTMSO)g(BF4) . In the case of M = Cu these ions are distorted from the regular octahedral structure. 

Sawateev et al. [244] have reported on tungsten oxides with regular octahedral 6- <—Cr2WOg) and with deformed... 

W(VI) compounds with 5cP electronic configuration, the EFG is reasonably weU described by the lattice contribution only. The regular octahedral WOs structure yields zero EFG in agreement with experiment, while the deformed tetrahedral W04 strucmre results in significant quadrupole coupling constants of either sign, e Q > 0 and also <0, depending on the distortion of the O4 tetrahedron. 

Tellurium crystallizes isotypic to a-selenium. As expected, the Te-Te bonds in the chain (283 pm) are longer than in selenium, but the contact distances to the atoms of the adjacent chains are nearly the same (Te- Te 349 pm). The shortening, as compared to the van der Waals distance, is more marked and the deviation from a regular octahedral coordination of the atoms is reduced (cf. Table 11.1, p. 111). By exerting pressure all six distances can be made to be equal (cf. Section 11.4). 

Tc2(CH3C00)4](Tc04)2. This compound was obtained by the slow oxidation of alcoholic solutions of the intermediate products of the synthesis of [Tc2(CH3COO)4Cl] and K2[Tc2(Ac)4C1]2 in air [58]. The oxidation yields several red transparent crystals of the regular octahedral form. 

This is an immediate consequence of the lowering of the symmetry as, even in the regular octahedral geometry, group theory tells us that the highest dimension of the irreducible representation is three. This is the basis of Crystal Field Theory, whose deeply symmetry-based formalism was developed by Bethe in 1929 [16]. 

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