Week 13 (Prep of cobalt complexes)

Question 1

Naming of Ligands

Answer 1

-if ligand is a simple anion (with -ide ending), “-ide” changes to “-o” (ex. chloride -> chloro)
-if ligand is polyatomic anion (with -ite or -ate ending), final “e” is changed to “-o” (ex. sulfate -> sulfo)
-if ligand is neutral, the common name is used (ex ethylenediamine)
EXCEPTIONS:
-water= aqua
-ammonia= ammine
-carbon monoxide= carbonyl

Question 2

naming of simple anion ligand

Answer 2

-if ligand is a simple anion (with -ide ending), “-ide” changes to “-o”
-(ex. chloride -> chloro)

Question 3

naming of polyatomic anion ligand

Answer 3

-if ligand is polyatomic anion (with -ite or -ate ending), final “e” is changed to “-o”
-(ex. sulfate -> sulfato)

Question 4

naming of neutral ligand

Answer 4

-if ligand is neutral, the common name is used
-(ex ethylenediamine)

Question 5

ligand naming exceptions

Answer 5

-water= aqua
-ammonia= ammine
-carbon monoxide= carbonyl

Question 6

prefixes for monodentate ligands

Answer 6

-di, tri, tetra, etc.

Question 7

prefixes for polydentate ligands

Answer 7

-bis, tris

Question 8

Complex formation vs Ligand substitution

Answer 8

-complex formation: did not have complex, added ligand to form complex
-ligand substitution: had complex, added ligand which replaced old ligand on metal

Question 9

Co(H₂O)₆²⁺ and CoCl₄²⁻ qualities

Answer 9

-Co(H₂O)₆²⁺ + 4 Cl⁻ -> CoCl₄²⁻ + 6(H₂O)
-Co(H₂O)₆²⁺ is pink, octahedral, and stable at low temps
-CoCl₄²⁻ is blue, tetrahedral, and stable at high temps

Question 10

how to calculate percent yield

Answer 10

-percent yield= [(actual yield)/(theoretical yield)] x 100
-actual yield is usually smaller than theoretical yield