Does the conditional divorce that I swore to my wife while in a state of extreme anger, with the words, "It is [a] divorce upon me: if you tell anyone anything I told you not to say, then you will be divorced by three," take effect, knowing that I did not intend divorce, but rather intended threat and intimidation, and can it be revoked by intention or expiation?

Since you did not intend to effect a divorce with this oath, but rather intended to threaten; you cannot retract this statement. The fatwa adopted by us is that if you break this oath, your wife will be divorced three times. Some scholars, like Shaykh al-Islam Ibn Taymiyyah, are of the view that divorce does not occur by breaking this oath, and that if you break it, an expiation for an oath becomes binding upon you.

The permissible oath is to swear by Allah Almighty. As for swearing by divorce, it is among the oaths of the dissolute, and it may lead to undesirable consequences, especially if it is with the triple divorce wording.