a) Write the ground state electron configuration for the Fe3+ cation. You can use the noble gas [...] notation to indicate the core electrons. Use the following format: [...] n sm b) Use the Tanabe-Sugano diagram on page 5 and identify the free ion ground state symbol (Russel-Saunders term) for Fe3+. c) Identify the octahedral ground state term symbols for Fe3+ in i) a weak octahedral ligand field and in ii) a strong octahedral ligand field. i) weak octahedral ligand field: ii) strong octahedral ligand field d) Determine the spin-only effective magnetic moment of Fe3+ in a i) weak octahedral ligand field: ii) strong octahedral ligand field You measured for the Fe3+ containing complex the following absorption peaks for d-d transitions. Table Q2. Peak Wavenumber / cm-1 1 12,500 log(s)/ dm³mol-1cm-1 0.05 Transition Notes 2 14,200 0.03 3 18,100 0.02 4 23,500 2.03 5 23,500 2.40 6 25,970 1.95 7 27,440 2.10 e) Sketch the uv-vis absorption spectrum in the diagram on page 8. The uv-vis spectrum doesn't have to be exactly to scale but needs to be conceptually correct. Use this Tanabe-Sugano diagram and determine A, for this Fe complex using the uv-vis peak data provided in table Q2. Racah parameter B = 700 cm 10 20 30 40 A₂ 3 2 L - /(3)301 40,000 30,000 18,000 ←v/cm1 60 AE 50 70 60 50 00 40 270 2F G60 E/B F 50 21 40 H F Dp "G 2 M 30 30 20 20 20- 28212 ATI 40 40 30 T₂ AL Ti -10 10 10- 6A T₂ 0 10 20 30 A/B 0 10 20 30 40 PIC⚫ f) Describe how you determined A g) Complete 'Table Q2' on page 7 by filling the column with the heading transitions with the electronic transitions (use proper notations) for each row. h) Based on the analysis of the Tanabe-Sugano diagram is this a high-spin or a low-spin complex? Explain. i) Use the spectrochemical series (see resource pages) and propose a ligand for the Fe3+ coordination compound that would likely form an octahedral complex with the spin-state you determined in Question 2 h). You need to provide a complete coordination compound with the complex written in square brackets and all necessary counter ions. j) Predict the effective magnetic moment for this octahedral Fe3+ complex in units of Bohr Magnetons. k) Determine the crystal field stabilization energy of the Fe3+ complex in units of A.. You are reducing the original octahedral Fe3+ complex to a tetrahedral Fen+ complex. This Fen+ containing tetrahedral complex has a spin-only effective magnetic moment of Heff -4.88(3)μB. 1) What is the oxidation state of the reduced iron? m) Draw the crystal field energy diagram of the tetrahedral complex. Label all d-orbitals and label the different energy levels with the proper symmetry species as used for orbitals. Indicate the tetrahedral field splitting energy in your diagram. n) Determine the crystal field stabilization energy in units of AT for this Fen+ tetrahedral complex.

a) Write the ground state electron configuration for the Fe3+ cation. You can use the noble gas [...] notation to indicate the core electrons. Use the following format: [...] n sm b) Use the Tanabe-Sugano diagram on page 5 and identify the free ion ground state symbol (Russel-Saunders term) for Fe3+. c) Identify the octahedral ground state term symbols for Fe3+ in i) a weak octahedral ligand field and in ii) a strong octahedral ligand field. i) weak octahedral ligand field: ii) strong octahedral ligand field d) Determine the spin-only effective magnetic moment of Fe3+ in a i) weak octahedral ligand field: ii) strong octahedral ligand field You measured for the Fe3+ containing complex the following absorption peaks for d-d transitions. Table Q2. Peak Wavenumber / cm-1 1 12,500 log(s)/ dm³mol-1cm-1 0.05 Transition Notes 2 14,200 0.03 3 18,100 0.02 4 23,500 2.03 5 23,500 2.40 6 25,970 1.95 7 27,440 2.10 e) Sketch the uv-vis absorption spectrum in the diagram on page 8. The uv-vis spectrum doesn't have to be exactly to scale but needs to be conceptually correct. Use this Tanabe-Sugano diagram and determine A, for this Fe complex using the uv-vis peak data provided in table Q2. Racah parameter B = 700 cm 10 20 30 40 A₂ 3 2 L - /(3)301 40,000 30,000 18,000 ←v/cm1 60 AE 50 70 60 50 00 40 270 2F G60 E/B F 50 21 40 H F Dp "G 2 M 30 30 20 20 20- 28212 ATI 40 40 30 T₂ AL Ti -10 10 10- 6A T₂ 0 10 20 30 A/B 0 10 20 30 40 PIC⚫ f) Describe how you determined A g) Complete 'Table Q2' on page 7 by filling the column with the heading transitions with the electronic transitions (use proper notations) for each row. h) Based on the analysis of the Tanabe-Sugano diagram is this a high-spin or a low-spin complex? Explain. i) Use the spectrochemical series (see resource pages) and propose a ligand for the Fe3+ coordination compound that would likely form an octahedral complex with the spin-state you determined in Question 2 h). You need to provide a complete coordination compound with the complex written in square brackets and all necessary counter ions. j) Predict the effective magnetic moment for this octahedral Fe3+ complex in units of Bohr Magnetons. k) Determine the crystal field stabilization energy of the Fe3+ complex in units of A.. You are reducing the original octahedral Fe3+ complex to a tetrahedral Fen+ complex. This Fen+ containing tetrahedral complex has a spin-only effective magnetic moment of Heff -4.88(3)μB. 1) What is the oxidation state of the reduced iron? m) Draw the crystal field energy diagram of the tetrahedral complex. Label all d-orbitals and label the different energy levels with the proper symmetry species as used for orbitals. Indicate the tetrahedral field splitting energy in your diagram. n) Determine the crystal field stabilization energy in units of AT for this Fen+ tetrahedral complex.

Physical Chemistry

2nd Edition

ISBN:9781133958437

Author:Ball, David W. (david Warren), BAER, Tomas

Publisher:Ball, David W. (david Warren), BAER, Tomas

Chapter12: Atoms And Molecules

Section: Chapter Questions

Problem 12.46E: Explain why assuming an effective nuclear charge, as used for our treatment of the helium atom in...

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