Advanced Inorganic Chemistry

Test 4

Name:  ________________________                                                                           May 1, 2017

77 possible

Spectrochemical series for ligands:  I- < Br- < S2- < SCN- < Cl- < NO2- < N3- < F- < OH- < C2O42- < H2O < NCS- < CH3CN < py < NH3 < en < bipy < phen < NO2- < PPh3 < CN- < CO

Spectrochemical series for metals:  Mn(II) < Ni(II) < Co(II) < Fe(III) < Cr(III) < Co(III) < Ru(III) < Mo(III) < Rh(III) < Pd(II) < Ir(III) < Pt(IV)

1.   (3 pts)  Sketch the neutral “acac” ligand. 

It is 2,4-pentanedione:

2.   (10 pts)  Draw both possible isomers of [CoCl3(NH3)3].  Name them; include the geometric isomer description and the oxidation state of the metal in the name.

http://upload.wikimedia.org/wikipedia/commons/6/69/Fac-trichlorotriamminecobalt%28III%29.png                       http://upload.wikimedia.org/wikipedia/commons/5/54/Mer-trichlorotriamminecobalt%28III%29.png                 

mer-triamminetrichlorocobalt(III)                    fac-triamminetrichlorocobalt(III)

3.   (8 pt)   Sketch a square planar palladium(II) complex with ox and two PPh3 ligands attached to it.

Something like this: 

This page:  21 pts

 

 


 

4.   (6 pts)  Name the following two geometries. 

structure 8-18                   structure 8-20

capped trigonal prism                                              square antiprism

5.   (5 pts)  Give the formula, including stereochemical configuration, for the following complex

structure 8-07   [trans-PtCl2(NH3)2]

6.   (6 pts)  Sketch the Berry pseudorotation.

7.   (2 pts)  The structure on the right (purple is manganese) can be considered to be a metal ______________ complex. cluster -1 pt for “cage”

 

 

 

 

 

 

 

 

 

This page:  19 pts

 

8.   (3 pts)  What is the oxidation state of the iron in [FeCl6]4–?  

Fe(II)

9.   (3 pts)  How many d electrons does iron have [FeCl6]4–?

Fe(II) has 6 d electrons

10. (3 pts)  Would you expect [FeCl6]4– to be a weak-field or a strong-field compound?  Why?

Since Br is low in the spectrochemical series for ligands, and the metal is in the middle of the spectrochemical series for metals, the compound is probably weak-field.

11. (1 pt)   Predict whether [FeCl6]4– would be high-spin or low spin.

High-spin  Must be consistent with above.

12. (4 pts)  Sketch the t2g and eg levels for [FeCl6]4–.  Include the correct number of electrons in these levels.

 

13. (5 pts)  Calculate the crystal-field stabilization energy (as a multiple of ΔO) for [FeCl6]4–.

CFSE = 0.4 ΔO × 4 - 0.6 ΔO × 2 = 0.4 ΔO         Must be consistent with above.

14. (3 pts)  What value of the spin-only magnetic moment, µeff/µB, would be expected for [FeCl6]4–?

S43

With 4 unpaired electrons, S = 2, so the magnetic moment would be expected to be about 4.9. 

This page:  22 pts


 

     (c)   + _____ ®  + 5          

15. (7 pts)  Sketch the splitting pattern of d orbitals expected for tetrahedral [CoCl4]2-.  Include the correct number of d electrons in the sketch.

1 pt for d7.  4 pts for t2 above e.  2 pts for high-spin.

16. (8 pts)  The position of CO in the spectrochemical series is explained by ligand field theory in terms of π-bonding.  Sketch a molecular orbital diagram illustrating how π-bonding increases ΔO when CO is coordinated to an octahedral metal. (Show ΔO before and after adding π-bonding.)

Ligands that act as π acceptor increase ΔO.

1 pt, metal t2g

1 pt, ΔO shown from t2g ® eg

1 pt, ΔO increased

1 pt, antibonding MO shown

2 pts, 3 empty ligand π orbitals

2 pts, bonding MO is lower & empty

This page:  15 pts