Gold

[budullewraagh]

I'm trying to make gold nanoshells and had an idea, but am unsure as to whether gold would be able to undergo oxidative insertion to add between a Si-Cl bond.

 

My idea was to take silica nanospheres, react with oxalyl or thionyl chloride to turn the hydroxyls (on the outside of the SiO2) into chlorides and then have the gold insert to form Si-Au-Cl. Furthermore I was wondering as to whether a reducing solution of HAuCl4 and NaBH4 would continue to add gold to form Si-Au-Au-Cl, Si-Au-Au-Au-Cl, etc.

 

The most obvious problem with this is that I can't think of too many divalent gold compounds. Apparently the oxidation state exists, but is only existent in "rare complexes." The only one I know of is [AuXe4]+2 but that is unstable and at +2 already. Are there any that are either at ground state or +1?

 

Also a possibility would be a +1 gold salt such as AuCl, but I'm not sure that it would insert well.

 

Also, does anyone here have any thoughts on my proposal?

[John Cuthber]

Interesting idea. I think thatif you maded SiCl bonds they would hydrolyse as soon as you took the stuff into suspension in water.

It would be interesting to reduce a gold salt in the presence of some nanoparticulate silica and see if the Au "plated" out onto the surface. I think that converting the "SiOH" to "SiSH" might help. Not sure about that but peopele seem to use thiols for putting monolayers onto gold electrodes (and I'm not sure how you would do it anyway).