DEAD- diethylazodicarboxylate

     O      O
    ||     ||
/\  /\     /\  /\
   O   N=N   O
Orange liquid of density 1.106 gcm-3 and a boiling point of 106oC at 13mm Hg.

Another molecule with a silly name, DEAD happens to be rather appropriately acronymed given the associated risks:

Stability- Stable, but...

Toxicology- Toxic.

Beyond having an entertaining name, DEAD (C6H10 N2O4 , synonyms Diazenedicarboxylic acid, diethyl ester; diethyl azodicarboxylate) is of note for its role in the Mitsunobu Reaction. This mild reaction is used for the activation of alcohols to nucleophilic attack, meaning the hydroxyl group can be replaced by a range of nucleophiles; an example of nucleophilic substitution. Triphenylphosphine is also required to obtain the following activation:

Ph3P + ROH + EtO2CN=NCO2Et --> Ph3PO+R + EtO2CN--N(H)CO2Et

The Intermediate obtained has a region of positive charge which is then vulnerable to nucleophilic attack:

 
R-CH-R                          R-CH-R
  |     + Nu-     -->             |        + Ph3P=O
 +OPPh3                           Nu

With secondary alcohols, this causes inversion of the oxygen substituted centre stereochemically, creating a different optical isomer. This is a result of the PPh3 group attached to the intermediate being very large stereochemically, so the incoming nucleophile attacks from the opposite side.


Also, my nickname at school, but this was more to do with corpse-like appearance than dubious stability and useful action upon alcohols...
Journal Ref: M.J.Arco, M.H.Trammel and J.D.White, Journal of Organic Chemistry Vol 41 Page 2075 (1976)