Ch.21 - Transition Elements and Coordination Chemistry

McMurry8th EditionChemistryISBN: 9781292336145Not the one you use?Change textbook

McMurry 8th Edition

Ch.21 - Transition Elements and Coordination Chemistry

Problem 21.128a

Chapter 21, Problem 21.128a

There are two possible [M(OH)4]- complexes of first-series transition metals that have three unpaired electrons.
(a) What are the oxidation state and the identity of M in these complexes?
(b) Using orbital diagrams, give a valence bond description of the bonding in each complex.
(c) Based on common oxidation states of first-series transition metals (Figure 21.6), which [M(OH)4]- complex is more likely to exist?
<QUESTION REFERENCES FIGURE 21.6>-

Verified step by step guidance

Identify the first-series transition metals that can form [M(OH)_4]^- complexes with three unpaired electrons. Consider the electronic configuration of these metals in their common oxidation states.

Determine the oxidation state of M in the [M(OH)_4]^- complex. Since the hydroxide ion (OH^-) has a charge of -1, and the overall charge of the complex is -1, calculate the oxidation state of M.

For each identified metal, draw the orbital diagram for the valence electrons in the oxidation state determined. Show how the electrons are distributed among the d orbitals, ensuring there are three unpaired electrons.

Use valence bond theory to describe the bonding in each complex. Consider the hybridization of the metal's orbitals and how they overlap with the orbitals of the hydroxide ligands.

Refer to Figure 21.6 to compare the common oxidation states of the identified metals. Determine which metal is more likely to exist in the [M(OH)_4]^- complex based on its stability and prevalence in that oxidation state.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Oxidation States of Transition Metals

The oxidation state of a transition metal indicates the charge it would have if all ligands were removed, and all bonding electrons were assigned to the more electronegative atom. Transition metals can exhibit multiple oxidation states due to their ability to lose different numbers of d-electrons. Understanding the common oxidation states helps in predicting the identity of the metal in complexes and their stability.

Valence Bond Theory and Orbital Diagrams

Valence Bond Theory explains how atomic orbitals combine to form bonds in molecules. Orbital diagrams visually represent the distribution of electrons in these orbitals, showing how unpaired electrons can participate in bonding. For transition metal complexes, the arrangement of d-orbitals and their interactions with ligands are crucial for understanding the geometry and bonding characteristics of the complex.

Ligand Field Theory

Ligand Field Theory extends the concepts of Valence Bond Theory by considering the effect of ligands on the energy levels of d-orbitals in transition metals. It explains how the presence of ligands can split the d-orbital energies, influencing the number of unpaired electrons and the overall stability of the complex. This theory is essential for predicting the likelihood of certain oxidation states and the formation of specific metal-ligand complexes.

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Guided course

02:40

Strong-Field Ligands result in a large Δ and Weak-Field Ligands result in a small Δ.

Related Practice

Textbook Question

For each of the following complexes, draw a crystal field energy-level diagram, assign the electrons to orbitals, and predict the number of unpaired electrons.

(a) [Pt(NH3)4]2+ (square planar)

Textbook Question

Draw a crystal field energy-level diagram, and predict the number of unpaired electrons for each of the following:

(a) [Mn(H2O)6]2+

Textbook Question

Cobalt(III) trifluoroacetylacetonate, Co(tfac)₃, is a sixc oordinate, octahedral metal chelate in which three planar, bidentate tfac ligands are attached to a central Co atom:

(a) Draw all possible diastereoisomers and enantiomers of Co(tfac)₃.

Textbook Question

Tell how many diastereoisomers are possible for each of the following complexes, and draw their structures.

(a) Pt(NH₃)₃Cl (square planar)

(b) [FeBr₂Cl₂(en)]^-

Textbook Question

Assign a systematic name to each of the following ions.

(a) [AuCl₄]^-

(b) [Fe(CN)₆]^4-

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Textbook Question

Two first-series transition metals have three unpaired electrons in complex ions of the type [MCl4]2-.

(a) What are the oxidation state and the identity of M in these complexes?

(b) Draw valence bond orbital diagrams for the two possible ions.