As I understood it, until the divorce papers are filed with the courts, and really until they are actually final, you are still considered married. Anything either of you do financially can cause problems later.
For example, if your ex were to go get a credit card and later has not paid the bill, the credit card company may come to you looking for payment because you were still married at the time.
You may want to check the laws in your state, but my advice is to wait on any purchases or loans until the divorce is final and hopefully your ex does the same.
Good luck to you.