How to bind the keyboard 'C-;'

[Vols]

Hi, group

I want the keyboard binding 'Control  ;' , for example, I tried:
(global-set-key  "\C-;" 'kill-this-buffe)
It doesn't work and comes with a "invalid modifier in string" error.

Actually i want to use 'C-;' to comment current line. (M-; add comment
at the end of the line). I used :

(global-set-key  "\C-;" 'my-comment-current-line)
(defun my-comment-current-line ()
  (interactive)
  (comment-region (line-beginning-position) (line-end-position)))

Thanks.
Vol.