UDMH

Unsymmetrical dimethylhydrazine (UDMH) (1,1-Dimethylhydrazine) is a hypergolic rocket fuel ingredient, often used in combination with the oxidiser, nitrogen tetroxide. UDMH is toxic, and can explode in the presence of oxidisers.

 H     CH3
  \\   /
   N-N                                                                    
  /   \\								        
 H     CH3                                                                    

• http://www.astronautix.com/props/n2o4udmh.htm