Meta-key Madness (argh!!)

[Howard Yeh!]

Hi,

I can't figure out how to bind "C-["

For some reason

(global-set-key "\C-[" 'insert-parentheses)

unbinds all my meta keys, and pressing "C-[" gives me the ESC key. What
gives?

I also has trouble binding c-i, m-i, because they are synonyms for
<TAB>. Though I have really ugly work around for them. Is there any
established way to deal with this sort of problems?