P.S. To my knowledge there arent any chemicals with the formula N2H2. I can only imagine that it would be terribly reactive and unstable. If you post an electron dot structure for hydrazine, I'll let you know how it looks.
Not especially unstable, but usually made in situ
from hydrazine and peroxides or chloramine-T etc, HN=NH is diimine.
Can be used in organic chemistry as a reducing agent in its own right, to e.g. convert olefins to alkanes stereospecifically in an electrocyclic reaction.
(edit typo correction)