I think my friend should give me a but of the profit if the sign a deal with the investor I set them up with.
Why would you feel that you should be getting this profit?
I fear that the problem which might arise should the friend later join an affiliate scheme.
You should not expect a payment just for introducing them.
I'm afraid I won't gain anything if it's not successful.
What was your reason for introducing them?  Unless part of the profit is written in a deal, their success does not necessarily mean that they should have to give you something.