Arkansas State University  Department of Chemistry and Physics
CHEM4204	Exam 4

1. Calculate the CFSE for high spin and low spin octahedral complexes of Co(gly)₃.  Which is preferred?  (12 points)

2. Determine which of these will be high spin, low spin or neither.  Show work or explain your answer.  (12 points)

 a)   Co(OH₂)₆⁺³

 b)   Cr(CN)₆^3-

 c)   MnCl₄^2-

 d)   RuCl₆^4-
 

3. For Cu(NO₂)₆^4-, 4 Cu-N bond distances are 205 pm while the two trans Cu-N bonds 231.3 pm.  Account for the difference in the bond lengths using Crystal Field Theory.  (Show the expected splitting diagram and label the orbitals.)  (12 points)

4. Using the Tanabe-Sugano diagram, determine the term symbol for the free ion ground state for Fe²⁺.  Determine the expected ground state term symbols for the high spin and low spin complexes.  Determine the spin state for Fe(CN)₆^4- and list all possible transitions. (12 points)

5. Determine whether the Co⁺² complex with phenanthroline (phen) will prefer to be octahedral or tetrahedral using CFSE.  Show work. (20 points)

6. Draw the expected splitting of the d orbitals for a square  planar geometry.        (10 points)

7. Calculate 10Dq for [Fe(OH₂)₅Cl]²⁺.  Will this be H.S. or L.S.?  Explain.  (10 points)

8. Draw the M.O. diagram for an Oh complex with six sigma donor ligands.  Draw in the electrons for a low spin d⁷ configuration.  Show how crystal field theory and the M.O. diagram give the same information.  (12 points)

BONUS.  Draw the splitting pattern for a d⁴ ion in a tetrahedral field.  Label the microstate as either singly (A), doubly (E) or triply (T) degenerate.   (5 points)