What is the ruling on swearing by divorce in a situation like this, and does the word "I divorce" mean the pronouncement of divorce?

A man's statement "I divorce" without attributing it to his wife or intending divorce does not effect a divorce. This is because the words of divorce must be explicitly or implicitly attributed to the wife. If they are not attributed to her—for example, if he says: "If you leave, divorce will occur," or "Do not leave except with my permission, for I have sworn by divorce," and then she leaves—no divorce occurs, because he failed to attribute it to her.