Ch.23 - Transition Metals and Coordination Chemistry
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- Complete the exercises below. Indicate the coordination number and the oxidation number of the metal for each of the following complexes: a. Na₂ [CdCl₄] b. K₂ [MoOCl₄] c. [Co(NH₃)₄ Cl₂] Cl
Problem 25
- Complete the exercises below. Indicate the coordination number and the oxidation number of the metal for each of the following complexes: e. NH₄[Cr(NH₃)₂(NCS)₄]
Problem 26
- Complete the exercises below. For each of the following molecules or polyatomic ions, draw the Lewis structure and indicate if it can act as a monodentate ligand, a bidentate ligand, or is unlikely to act as a ligand at all: a. ethylamine, CH₃CH₂NH₂, b. trimethylphosphine, P(CH₃)₃.
Problem 27
- Complete the exercises below. Polydentate ligands can vary in the number of coordination positions they occupy. In each of the following, identify the polydentate ligand present and indicate the probable number of coordination positions it occupies: a. [Co(NH₃)₄ (o-phen)] Cl₃.
Problem 29
- Complete the exercises below. For each of the following pairs, identify the molecule or ion that is more likely to act as a ligand in a metal complex: a. acetonitrile (CH₃CN) or ammonium (NH₄⁺),
Problem 31
- Complete the exercises below. Write the formula for each of the following compounds, being sure to use brackets to indicate the coordination sphere: e. bis(ethylenediamine)zinc(II) tetraiodomercurate(II).
Problem 35
- Complete the exercises below. Write the formula for each of the following compounds, being sure to use brackets to indicate the coordination sphere: e.g., tris(ethylenediamine)rhodium(III), tris(oxalato)cobaltate(III).
Problem 36
- Complete the exercises below. Write the names of the following compounds, using the standard nomenclature rules for coordination complexes: d. [Pt(H₂O)₄(C₂O₄)]Br₂
Problem 37
- Complete the exercises below. Write names for the following coordination compounds: d. [Ir(NH₃)₄(H₂O)₂](NO₃)₃
Problem 38
- Complete the exercises below. Consider the following three complexes: (Complex 1) [Co(NH₃)₄Br₂]Cl (Complex 2) [Pd(NH₃)₂(ONO)₂] (Complex 3) [V(en)₂Cl₂]⁺. Which of the three complexes can have: a. geometric isomers, b. linkage isomers, c. optical isomers, d. coordination-sphere isomers?
Problem 39
- Complete the exercises below. A four-coordinate complex MA₂B₂ is prepared and found to have two different isomers. Is it possible to determine from this information whether the complex is square planar or tetrahedral? If so, which is it?
Problem 41
- Complete the exercises below. Consider an octahedral complex MA₃B₃. How many geometric isomers are expected for this compound? Will any of the isomers be optically active? If so, which ones?
Problem 42
- Complete the exercises below. Determine if each of the following complexes exhibits geometric isomerism. If geometric isomers exist, determine how many there are. c. octahedral [Fe(o-phen)₂ Cl₂]⁺.
Problem 43
- Complete the exercises below. Determine if each of the following complexes exhibits geometric isomerism. If geometric isomers exist, determine how many there are. c. Square-planar [Pd(en)(CN)₂].
Problem 44
- Complete the exercises below. Determine if each of the following metal complexes is chiral and therefore has an optical isomer: b. octahedral trans-[Ru(bipy)₂Cl₂].
Problem 45
- Complete the exercises below. Determine if each of the following metal complexes is chiral and therefore has an optical isomer: a. square planar [Pd(en)(CN)₂].
Problem 46
- Complete the exercises below. Determine if each of the following metal complexes is chiral and therefore has an optical isomer: b. octahedral [Ni(en)(NH₃)₄]²⁺.
Problem 46
- Complete the exercises below. Determine if each of the following metal complexes is chiral and therefore has an optical isomer: c. octahedral cis-[V(en)₂ClBr].
Problem 46
- Complete the exercises below. a. If a complex absorbs light at 610 nm, what color would you expect the complex to be? b. What is the energy in joules of a photon with a wavelength of 610 nm? c. What is the energy of this absorption in kJ/mol?
Problem 47
- Complete the exercises below. a. A complex absorbs photons with an energy of 4.51 x 10⁻¹⁹ J. What is the wavelength of these photons? b. If this is the only place in the visible spectrum where the complex absorbs light, what color would you expect the complex to be?
Problem 48
- Complete the exercises below. Identify each of the following coordination complexes as either diamagnetic or paramagnetic: a. [ZnCl₄]²⁻ b. [Pd(NH₃)₂ Cl₂]
Problem 49
Problem 52a
The lobes of which d orbitals point directly between the ligands in a. octahedral geometry,
Problem 52b
The lobes of which d orbitals point directly between the ligands in b. tetrahedral geometry?
- Complete the exercises below. a. Sketch a diagram that shows the definition of the crystal-field splitting energy (∆) for an octahedral crystal-field. b. What is the relationship between the magnitude of ∆ and the energy of the d-d transition for a d¹ complex? c. Calculate ∆ in kJ/mol if a d¹ complex has an absorption maximum at 545 nm.
Problem 53
Problem 54
As shown in Figure 23.26, the d-d transition of [Ti(H2O)6]³⁺ produces an absorption maximum at a wavelength of about 500 nm .
a. What is the magnitude of ∆ for [Ti(H2O)6]³⁺ in kJ/mol?
b. How would the magnitude of ∆ change if the H2O ligands in [Ti(H2O)6]]³⁺ were placed with NH3 ligands?
- Complete the exercises below. Give the number of (valence) d electrons associated with the central metal ion in each of the following complexes: a. K₃ [TiCl₆], b. Na₃ [Co(NO₂)₆], c. [Ru(en)₃] Br₃, d. [Mo(EDTA)] ClO₄, e. K₃ [ReCl₆].
Problem 57
- Complete the exercises below. Give the number of (valence) d electrons associated with the central metal ion in each of the following complexes: a. K₃[Fe(CN)₆] b. [Mn(H₂O)₆](NO₃)₂ c. Na[Ag(CN)₂] d. [Cr(NH₃)₄Br₂]ClO₄ e. [Sr(EDTA)]²⁻
Problem 58
Problem 59
A classmate says, “A weak-field ligand usually means the complex is high spin.” Is your classmate correct? Explain.
Problem 60
For a given metal ion and set of ligands, is the crystal-field splitting energy larger for a tetrahedral or an octahedral geometry?
- Complete the exercises below. For each of the following metals, write the electronic configuration of the atom and its 2+ ion: a. Mn. Draw the crystal-field energy-level diagram for the d orbitals of an octahedral complex, and show the placement of the d electrons for each 2+ ion, assuming a strong-field complex. How many unpaired electrons are there in each case? b. Ru. Draw the crystal-field energy-level diagram for the d orbitals of an octahedral complex, and show the placement of the d electrons for each 2+ ion, assuming a strong-field complex. How many unpaired electrons are there in each case? c. Rh. Draw the crystal-field energy-level diagram for the d orbitals of an octahedral complex, and show the placement of the d electrons for each 2+ ion, assuming a strong-field complex. How many unpaired electrons are there in each case?
Problem 61