Generally there is no personal liability under law for corporate debts so you couldn’t just go after the new company. The property, however, remains assessed with taxes and remains subject to distress. So while a new corporate owner would not be personally liable, the business property could be seized for the taxes.
§58.1-3941 establishes a lien on the property that is valid against even a bona fide purchaser. This effectively places the burden on the new owner to pay the taxes. He then may have a claim against the seller. You may also want to inquire if there are any payments remaining between the parties, as you could issue a Treasurers’ Lien to the new owner for the payments he owes the old owner. Either of these may be useful to you as you continue to pursue collections.