What is the ruling regarding divorcing one's wife over the phone before consummation, while in a state of extreme anger and ignorance of Sharia rulings? What are the consequent rulings, such as the necessity of a new marriage contract and a new dowry? And does the divorce actually take place at all?

If you utter a divorce statement while in a state of extreme anger that makes you lose awareness of what you are saying, then the divorce does not take effect, because accountability is lifted from you. The same applies if your tongue slips with a divorce statement without intending to utter it. It must be emphasized that the anger which prevents divorce from taking effect is that which causes the person to completely lose awareness, and this is rare. A slip of the tongue occurs when you intend to say one word, but divorce comes out unintentionally, and not when you intend to utter divorce without intending for it to take effect. Ignorance of the ruling does not prevent divorce from taking effect.