That's highly unlikely. Sure you can capture an ip and see who it belongs to but that's a real stretch. If someone is at their desk behind the corporate firewall and you get the ip belonging to a company you have no way of knowing who in that company was on your site.
Why is that valuable anyway? If they are interested they will contact you. Your efforts would be better spent closing them while they are on your site with good copy. Move on from these guys with their promises or I fear you will regret it.
Best.