Octahedral complex ions

According to the above classification, the structures of LiNb(Ta)F6 and Li2Nb(Ta)OF5 should be composed of lithium cations and isolated octahedral complex ions, Nb(Ta)F6 or Nb(Ta)OF52, respectively. It is known, however, that the structure of these compounds consists only of octahedrons linked via their vertexes in the first case, and via their sides in the second case. The same behavior is observed in compounds containing bi- and trivalent metals. 

Notice that in an octahedral complex ion such as [Cr(NH3)4Cl2]+ there is a possibility of observing isomers. The two chlorine atoms may occupy octahedral positions which are next to each other on the same side of the metal atom, or positions located on opposite sides of the - metal atom (see Figure 22-4). The isomer in which the two similar groups are located on the same side of the metal atom is called the cis-isomer, and the other is called the trans-isomer. 

C18-0121. Zinc forms an octahedral complex ion with three bidentate oxalate ions ... 

Figure 20-12 summarizes the electrical interactions of an octahedral complex ion. The three orbitals that are more stable are called 2 g orbitals, and the two less stable orbitals are called Sg orbitals. The difference in energy between the two sets is known as the crystal field splitting energy, symbolized by the Greek letter h. 

Fig. 5-12.—The representation of alternative extreme types of electronio structures for the octahedral complex ion [Co(NH ) ]++4 On the left is a representation of the structure with extreme electrostatic bonds. The cobalt atom is represented as having a positive Electric charge, 3+. At the right is represented the structure in which normal covalent bonds are between the cobalt atom and the surrounding nitrogen atoms, as well as between the nitrogen atom and its three attached hydrogen atoms. This structure places the charge 3— on the cobalt atom and 1+ on each nitrogen atom.

In a few cases an unshared electron pair seems to have no effect on bond directions. This is observed98 for Se(IV) in the octahedral complex ion [SeBre]— and for Sb(III) in [SbBr ]. ... 

NMR studies of the fluxionality of octahedral transition element dithiocarbamates were performed by Pignolet and coworkers.65 The synthesis and X-ray structure of the pseudo-octahedral complex ion (40) were described by McCleverty et al. in their investigations of the inorganic aspects of rubber vulcanization.66 Our investigations point to the existence of a barium analogue.67... 

Geometrical isomerism also occurs in octahedral complex ions. For example, the compound [Co(NH3)4Cl2]Cl has cis and trans isomers (Fig. 20.12). 

Draw the d-orbital splitting diagrams for the octahedral complex ions of each of the following. 

It is common practice to consider the traditional Werner octahedral complex ions [MlLNle]" [M = Co(III), Rh(III), Ir(III), Cr(III), Ru(III), Pt(IV) LN = donor atom of unidentate or polydentate ammine or amine] as well as square-planar [M(LN)4p [M = Pt(II), Pd(II)] as kinetically inert compounds. Bound ammonia is generally less labile than bound water, and it has been suggested that this observation can be related to the presence of an extra and exposed electron pair in water. This may make it more sensitive to electrophilic groups in the solvation sheath, which could assist its dissociation from the metal ion (274). If we take the stance of assigning lability as a property of the ligand in such complexes, then ammonia and amines in general can be... 

Octahedral complex ions, are generally very stable GeFg , like... 

The octahedral complex ions [FeClg] and [Fe(CN)g] are both paramagnetic, but the former is high spin and the latter is low spin. Identify the d-electron configurations in these two octahedral complex ions. In which is the octahedral field splitting greater. How does the CFSE differ between the complexes ... 

Experiments can measure not only whether a compound is paramagnetic, but also the number of unpaired electrons. It is found that the octahedral complex ion [Fe(CN)g] has... 

The octahedral complex ion [MnClg] has more unpaired spins than the octahedral complex ion [Mn(CN)g] . How many unpaired electrons are present in each species Explain. In each case, express the CFSE in terms of A<,. 

Various ways in which metal complexes can be represented, illustrated for the simple octahedral complex ion [IrClg]2-. 

Figure 22.10 Geometric (cis-trans) isomerism. A, The c/s and trans isomers of the square planar coordination compound [Pt(NH3)2Cl2]. B, The c/s and trans isomers of the octahedral complex Ion [Co(NH3)4Cl2]. The colored shapes represent the actual colors of the species.

SAMPLE PROBLEM 22.5 Identifying Complex Ions as High Spin or Low Spin Problem Iron(II) forms an essential complex in hemoglobin. For each of the two octahedral complex ions [Fe(H20)6]"" and [Fe(CN)6]" , draw an orbital splitting diagram, predict the number of unpaired electrons, and identify the ion as low spin or high spin. 

Why is Co(NH3)e diamagnetic whereas CoFe is paramagnetic Some octahedral complex ions have the same r/-orbital splitting diagrams whether they are high-spin or low-spin. For which of the following is this true ... 

Why do tetrahedral complex ions have a different crystal field diagram than octahedral complex ions What is the tetrahedral crystal field diagram Why are virtually all tetrahedral complex ions "high spin" ... 

CoBrg is an octahedral complex ion. Since tetrahedral rf-orbital splitting is less than one-half the octahedral rf-orbital splitting, the octahedral complex ion... 

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