Fragmentation reactions, unstable intermediates and

4 Fragmentation reactions, unstable intermediates and formation of complexes or weakly bound species 

Photolysis reactions involving the formation of carbenes, nitrenes or ylides were addressed mainly by the groups of Wentrup, Sanders, Ault, Fausto, Schreiner, Stanton, Willner and Wierzejewska. 

The tetrazoles family of compounds represents an important source of nitrenes, carbenes and ylides when subjected to UV irradiation. Baskir et isolated 5-amino- and 5-(dimethyl)amino-2-methyl- 

IR spectra obtained. The experimentally observed low frequency and low intensity values of the IR band associated with the Vas(CNN) stretching mode suggest an increase in the carbene component in the structure of the amino-substituted nitrile imines. Other photoproducts could also be identified, closely following the previous study by Gomez-Zavaglia et al. on this type of molecules. 

Pagacz-Kostrzewa, Krupa and Wierzejewska reported the photochemistry of (tetrazol-5-yl)acetic acid (TA Fig. 32). Three out of the nine theoretically predicted stable structures for this compound were observed in solid argon. Both broadband and narrowband UV irradiations of (tetrazol-5-yl)acetic acid were conducted, the main observed photoproducts being carbodiimidylacetic acid (CA) and (lFf-diazirin-3-yl)acetic acid (DA). 

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