Question

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

Answer 1

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.