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Ch.21 - Transition Elements and Coordination Chemistry
McMurry - Chemistry 8th Edition
McMurry8th EditionChemistryISBN: 9781292336145Not the one you use?Change textbook
All textbooksMcMurry 8th EditionCh.21 - Transition Elements and Coordination ChemistryProblem 21.87a
Chapter 21, Problem 21.87a

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)]-

Verified step by step guidance
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Step 1: Understand the concept of diastereoisomers. Diastereoisomers are stereoisomers that are not mirror images of each other. They occur in compounds with multiple chiral centers or in coordination complexes with different spatial arrangements.
Step 2: Analyze the first complex, Pt(NH3)3Cl, which is square planar. In square planar complexes, the ligands are arranged in a plane around the central metal atom. Consider the possible arrangements of the three NH3 ligands and one Cl ligand around the Pt center.
Step 3: Determine the possible diastereoisomers for Pt(NH3)3Cl. Since it is a square planar complex, check for any possible geometric isomers by arranging the ligands differently around the central metal.
Step 4: Analyze the second complex, [FeBr2Cl2(en)]-. This is an octahedral complex with two bidentate ethylenediamine (en) ligands and two different monodentate ligands (Br and Cl).
Step 5: Determine the possible diastereoisomers for [FeBr2Cl2(en)]-. Consider the different ways the Br and Cl ligands can be arranged around the Fe center, taking into account the bidentate nature of the en ligands, which can lead to cis and trans isomers.

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Key Concepts

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

Diastereoisomers

Diastereoisomers are stereoisomers that are not mirror images of each other. They occur in molecules with multiple chiral centers or in coordination complexes where different arrangements of ligands can lead to distinct spatial configurations. Understanding diastereoisomers is crucial for determining the number of possible isomers for a given complex, as they can exhibit different physical and chemical properties.

Coordination Complexes

Coordination complexes consist of a central metal atom bonded to surrounding ligands, which can be neutral molecules or ions. The geometry of these complexes, such as square planar or octahedral, influences the arrangement of ligands and the potential for isomerism. Recognizing the geometry is essential for predicting the number of diastereoisomers, as it determines how ligands can be arranged around the metal center.
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Chirality in Coordination Compounds

Chirality refers to the property of a molecule that makes it non-superimposable on its mirror image, often due to the presence of chiral centers. In coordination compounds, chirality can arise from the arrangement of ligands around a metal center. Identifying chiral configurations is important for determining the number of diastereoisomers, as each unique arrangement can lead to different stereoisomers.
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Related Practice
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

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>-

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.

(c) Based on common oxidation states of first-series transition metals (Figure 21.6), which ion is more likely to exist?

<QUESTION REFERENCES FIGURE 21.6>

Textbook Question

Constitutional isomers of a ruthenium(II) coordination compound are shown below.

(a) Give the formula and name for structures 1-3.

(b) Which structures are linkage isomers? 

(c) Which structures are ionization isomers?