Tetrazene, HNNNHNH

No paper dealing with HNNNHNH2 seems to have been published. Organic derivatives can be prepared by reacting diazonium salts with hydrazines which are substituted at one nitrogen. The number of the compounds known is limited see [3] for a review. 

The intermediate formation of the cis isomer of 2-tetrazene is supposed to occur during protolysis of 5,5-dimethyl-1,4-bis(trimethylsilyl)-4,5-dihydro-1H-5-silatetrazole by a four-molar quantity of CF3COOH in CH2CI2 at 195 K. However, only the decomposition products NH3 and HN3 were identified [7]. 

The vertical ionization potentials (IP) in the He I photoelectron spectrum of trans-2-tetra-zene were assigned with the aid of a CNDO/S calculation (assuming sp hybridization at the amino nitrogens)  

The first band exhibits a vibrational splitting of 650 cm The n character of the highest occupied MO was taken to indicate a considerable amount of conjugation along the nitrogen chain [9]. 

Based on the observed intensities, the first UV absorptions of R2NNNNR2 can be assigned to the energetically closely related n r-n and n -n transitions [12]. The maximum absorption was found in the range 277 to 292 nm with extinction values ranging from 5800 to 8300 L-mor cm [12, 15, 16]. 

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