Crystal field splitting diagrams, 669

C20-0014. Draw crystal field splitting diagrams that show the electron configurations for the following complex ions (a) [Cr (H2 (b) [IrCle] (c) [V (en)3] and (d) [NiCl4] (tetrahedral). 

C20-0073. Draw a crystal field splitting diagram that illustrates the electron transfer reaction of the simple iron redox protein shown in Figure 20-29a. 

Fig. l.i. Crystal field splitting diagrams for (a) octahedral MLh, (b) tetrahedral ML4, (c) square planar ML4, (d) square pyramidal MLS and (e) trigonal bipyramidal ML5. 

We may use exactly similar arguments to obtain total CFSE terms for the various d electron configurations within a tetrahedral crystal field. It is quite possible to construct crystal field splitting diagrams for any of the other geometries commonly adopted in transition-metal complexes, and to calculate the appropriate CFSE terms. 

A This involves comparing 0Dq with the pairing energy (PE) to determine that the complex is low spin. The crystal field splitting diagram shows the electron configuration from which the value of the CFSE can be calculated ... 

Develop a crystal field splitting diagram for the d orbitals of the metal in a trigonal bipyramidal complex [ML-] showing, qualitatively, how the energies of each of the d orbitals change. 

Figure A.4 The development of a crystal field splitting diagram for a trigonal bipyramidal complex,...

Figure 9.5 Crystal field splitting diagram for V0(H20)52+. [Reproduced with permission from Ophardt and Stupgia.12]...

The [Ni(CN)4] ion, which has a square-planar geometry, is diamagnetic, whereas the [NiC ] ion, which has a tetrahedral geometry, is paramagnetic. Show the crystal field splitting diagrams for those two complexes. 

Companion, A. L., Komarynsky, M. A. (1964) Crystal field splitting diagrams. J. Chem. Ednc. 41,257. 

Fig. 20.8 Crystal field splitting diagrams for octahedral (left-hand side) and tetrahedral (right-hand side) fields. The splittings are referred to a common barycentre. See also Figure 20.2.

Fig. 20.10 Crystal field splitting diagrams for some common fields referred to a common barycentre splittings are given with respect to For tetrahedral splitting, see Figure 20.8.

Nickel(II) complexes in which the metal coordination number is 4 can have either square-planar or tetrahedral geometry. [NiC ] is paramagnetic, and [Ni(CN)4] is diamagnetic. One of these complexes is square planar, and the other is tetrahedral. Use the relevant crystal-field splitting diagrams in the text to determine which complex has which geometry. 

Which of these crystal-field splitting diagrams represents (a) a weak-field octahedral complex of Fe, (b) a strong-field octahedral complex of Fe, (c) a tetrahedral complex of Fe , (d) a tetrahedral complex of Ni (The diagrams do not indicate the relative magnitudes of A.) [Section 23.6]... 

The red color of ruby is due to the presence of Cr(III) ions at octahedral sites in the close-packed oxide lattice of AI2O3. Draw the crystal-field splitting diagram for Cr(III) in this environment. Suppose that the ruby crystal is subjected to high pressure. What do you predict for the variation in the wavelength of absorption of the ruby as a function of pressure Explain. 

The crystal field splitting diagrams for the five d-orbitals in different coordination geometries. 

Why do you think Cr(l-norbornyl)4 (with a structure analogous to 15.1) is diamagnetic Write a crystal field splitting diagram for the molecule. On the basis of your results, predict the magnetic behavior of Cr(l-nor-bornyl)4. 

Four-coordinate nickel(II) complexes exhibit both square-planar and tetrahedral geometries. The tetrahedral ones, such as [NiCy, are paramagnetic the square-planar ones, such as [Ni(CN)4] , are diamagnetic. Show how the d electrons of nickelfll) populate the d orbitals in the appropriate crystal-field splitting diagram in each case. 

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