How would I form #"Na"_4"SiO"_4# from silicon dioxide? How about forming #"Na"_4"ZrO"_4# from zirconia?

1 Answer
Dec 29, 2015

Just a note: I'm only theorizing here, so ask your professor what he or she thinks as well.

For the silicon dioxide, you might want to consider the following reaction with sodium oxide:

#2"Na"_2"O" + "SiO"_2 -> "Na"_4"SiO"_4#

One way you may be able to proceed is to react with tosyl chloride, #"TsCl"# in pyridine, to form a sulfonate ester of the original silicate.

After that, the sulfonate ester should become a great leaving group (the pKa of sulfonic acid is about #-6.5#) for a nucleophilic attack, such as via 4 equiv. of sodium ethoxide (sealed away from oxygen in a desiccator), #"NaOCH"_2"CH"_3#.

Here's what I'm thinking:

Silicon-oxygen bonds are generally known to be pretty flexible, so I'm thinking that should help during the proposed #"S"_N2# reaction with the sodium ethoxide.

For zirconia (#"ZrO"_2#), you might be able to do a similar reaction with sodium oxide, but then use an alkali propoxide instead of sodium ethoxide.

#2"Na"_2"O" + "ZrO"_2 -> "Na"_4"ZrO"_4#

But again, ask your professor what he or she thinks too. I've never worked with zirconium before.