Tenant owes/selling home

I’m sure I’ve seen a thread on this but I can’t find it.

I have tenants who are moving out to a family owned property. They owe back rent. They claim they are selling to a family member.

The plan is that they use the proceeds from sale to pay me back, I run background check and new owners are (hopefully) cleared to move in. I haven’t been questioned (current tenants are fine, but I suspect new tenants will complain) but what is the legal basis for refusing to start any business with new owners until the old owners pay for back rent?

I have some concerns that family members will not be able to come up with the cash and the current owners will be gone, leaving the mobile home sitting and me still owed $. I guess my alternative would be to negotiate to purchase the home less amount owed (don’t really want it) or file for eviction and judgement. Any other ideas? I just feel like they have made the sale very awkward with owing back rent and a lot of buyers won’t be comfortable with turning over cash but not being allowed to move in yet.

Could you put the onus on the buyers/tenants to come with the back rent? Make it part of the lease that they pay back rent - they can negotiate with the seller as they please to make that happen?