Question re: Tax implications for Seller leaving money in the deal

[Shan Radhakr]

I wanted to ask a quick question to see anyone here has bought a property where the Seller is leaving money out of the deal's proceeds in the deal? I'm trying to figure out if the Seller will be taxed immediately on that money if they never touch it and it remains in the deal.  The Seller is not interested if there is immediate tax payment.   

If anyone has done something similar, I'd like to get some insight on how the deal was structured.  

Thank you. 

Shankar