The synthesis of VO(acac)2 is straightforward. As the students
add the carbonate solution, the evolution of CO2 is a useful
indication that the deprotonation is occurring. When the addition
of more carbonate solution does not produce any further
effervescence, the deprotonation is complete. Other bases such
as sodium acetate could have been used at this stage but
carbonate was chosen to expose the students to a different
method of determining when the appropriate amount of based
had been added. There is potential for excess carbonate, or
perhaps hydroxide formed due to the presence of carbonate, to
coordinate to the vanadium and decrease the yield of product.
During the addition of base, the product precipitates out of
solution and in the end the mixture is a thick suspension that is
filtered to isolate the product. After washing with water and
allowing the product to dry, a blue-green solid is collected.
Characterization by IR spectroscopy allows for the observation
of the strong VdO peak at 995 cm1.