Terminal applications have to fit keystrokes in a single byte which means that not all Ctrl+Key combinations can be represented. You can only use characters from the third column in this
ascii table (you can use the ones from the fourth column as well, but it will have the same effect as using the same row third column character). Also, you probably shouldn't use Ctrl-[ because that's the same as escape. So, no you can't bind Ctrl-;