C corp dissolved- can it issue something like K-1 for friends and family investors for them to write off their investment?

K1's aren't used for a Form 1120 even though a Sch K of 1120 is part of the Form 1120 itself. it's very rare to make investments into any other form of busines in general, the effect that C corp dissolution has on shareholders depends on the financial situation of the corp and on how the C corp dissolves; For tax purposes, the IRS treats a corp dissolution the same as a stock sale. If the corp distributes an amount greater than shareholders' basis in their stock, then the corp reports a loss on its final tax return. friends and family investors need to claim losses on their 1040s.

As backup for friends and family writing off investment what documentation from the company is needed
?

I guess The corp's Sch D of 1120 is one of them.