Page 54 - Arrow Pushing in Inorganic Chemistry A Logical Approach to the Chemistry of the Main Group Elements

A COLLECTION OF BASIC CONCEPTS
34
−
+
The oxo-bridged P –O–I intermediate may now react in a number of different ways. A
fluoride could depart from the anionic iodine and reattach to the cationic phosphorus center,
as shown below:
F − F
F F F F
I F F
F F F F
O F O I O I
+ F F F (1.68)
+ P F F P F F P F F
F − F
F F F
F F F
A second fluoride could then attack the neutral phosphorus center, leading to the final prod-
ucts PF and IOF :
5
5
F F
F F
F F
O I F O I
F F F F
− P F F P F F
F F − F
F F
F F (1.69)
F F
− +
O F −
F P F + I + F
F F
F F F

Other pathways are also conceivable for the initially formed oxo-bridged pathway.
For example, a 1,3-shift of a fluoride provides “quick” access to the neutral intermediate
F P–O–IF :
4
6
F
F − F F
F F F
I F I
F F F
O F O
F (1.70)
+ P F F P F
F F
F
F
A second fluoride 1,3-shift, along with cleavage of the I–O bond, could then lead to the
final observed products.

F
F
F
F I F F
F +
O F + F F
F F P − I (1.71)
F F O F
F P F F
F
F