Can. J. Chem. 56, 1657Chem. 56, (1978.Decompositions of tetramethyl-2-tetrazene (TMT) under acidic conditions were investigated by product analysis and by nmr and esr spectroscopic monitors. Photolysis in acetonitrile containing trifluoroacetic acid generated the dimethylaminium radical which added efficiently to an olefinic double bond. Some adducts contained a (CH3),NCH2-moiety, the immediate precursor of which could be CH2=N(CH3),+ species. Photolytic addition of TMT to norbornenes generated 2-norbornyl radicals that underwent coupling through the exo or endo side to give the dimers. Thermal decomposition in sulfuric acid in the presence of toluene gave N,N-dimethyltoluidines, N-methylphenethylamine, benzyltoluenes, and a plethora of other minor products in addition to a large amount of formylidene methylamine. The last compound was the major product when thermal decomposition of T M T was carried out in trifluoroacetic acid in the presence of toluene or anisol; amination products of aromatic substrates were low and contained only ortllo and porn isomers. TMT dissolved in these solvents exhibited the esr signal of the stable T M T t (the tetrazene cation radical) which did not react with cyclohexene. In concentrated sulfuric acid, T M T was decomposed in less than 15 min giving formylidene methylamine and dimethylamine as shown by nmr. In trifluoroacetic acid, the esr signal of tetramethylhydrazine cation radical ( T M H t ) emerged after the TMT solution was irradiated ; no dimethylaminium radical signal could be detected. The relationship of TMTf and TMHC with formation of the observed products remains unclear. Chem. 56, 1657Chem. 56, (1978.On a Ctudie, a I'aide de I'analyse des produits et par etudes spectroscopiques rmn et rpe la decomposition de la tetrarnethyltetrazene-2 (TMT) dans des conditions acides. La photolyse dans I'acetonitrile contenant de I'acide trifluoroacetique conduit a la formation de radical dimethylaminium qui s'additionne d'une f a~o n efficace a la double liaison olkfinique. Quelques produits contenaient une portion (CH3),NCH2-dont le prkcurseur immkdiat serait I'espece CH2N(CH3),+. L'addition photolytique du TMT aux norbornenes conduit a des radicaux norbornyl-2 qui subissent des couplages par les faces exo ou erldo pour conduire a des dimeres. La decomposition thermique dans I'acide sulfurique en presence de toluene conduit aux N,N-dimethyltoluidines, a la N-methylphenethylamine, aux benzyltoluenes et a toute une strie d'autres produits mineurs en plus d'une grande quantitt de formylidene methylamine. Ce dernier conrposk est le produit majeur lorsque la dCcomposition therrnique du TMT est effectuee dans I'acide trifluoroacetique en presence du toluene ou d'anisol; les produits d'amination des substrats aromatiques sont faibles et contiennent uniquement les isomeres orflro et pnrn. Lorsque le TMT est dissous dans ces solvants, il presente un signal rpe correspondant a I'entite T M T t (le radical cation tetraztne) qui ne rtagit pas avec le cyclohexene. Dans l'acide sulfurique co...