Difference between GUI/terminal when using "kbd" macro

[Felix Crux]

Hello,

I recently ran across a perplexing problem that I can't find the answer
to in the documentation.

The following snippet in my init file works just as one would expect in
both graphical (GTK+) and terminal instances of Emacs:

  (global-set-key [?\C-x ?\e] 'save-buffers-kill-emacs)

However, this version, which I thought to be identical (but more readable),
only works in graphical sessions:

  (global-set-key (kbd "C-x <escape>") 'save-buffers-kill-emacs)

When attempting to use it in a terminal, the status line simply displays
"C-x ESC-", as though waiting for more input.

Invoking emacs-version gives me "GNU Emacs 23.4.1 (x86_64-pc-linux-gnu,
GTK+ Version 2.24.10) of 2012-09-08 on trouble, modified by Debian".

I'd be most grateful if someone would point me in the right direction to
understand this. Thank you,

Felix C.