Chemistry / Chem. formula search engine?

[Genecks]

I'm trying to find a search engine that allows me to use superscripts, subscripts, misc. in order to find information about certain formulas.

 

For example, I've tried typing in [math][Cu(NH_{3})_{4}]^{2+}[/math].

I got some information, but I had to shove things around and figure it out.

But for a majority of things like that, I can't find a good .gov or .org website to help me out.

 

I don't want to buy tons of books, so I'm wondering if anyone knows of some good, very good, super-duper freaking awesome websites.