ELECTRONIC-STRUCTURE AND GAS-PHASE THERMOLYSIS OF 2-TETRAZENES WITH ACYCLIC OR CYCLIC AMINO-GROUPS STUDIED BY PHOTOELECTRON-SPECTROSCOPY

The electronic structures and the gas-phase thermolyses of the 2-tetrazenes 2-13 have been studied by He(I) photoelectron spectroscopy. The compounds are characterized by at least three ionization potentials with energies less than 10 eV which are assigned to the molecular orbitals pi3 (HOMO), n+, pi2, and n-. In the thermolyses either the formal disproportionation products (amine and imine) of the respective aminyl radical are found, or the latter is stabilized by loss of an alkyl radical affording also an imine. Further products which can be explained by radical reactions are detected in flash vacuum pyrolyses. The tricyclic cis-2-tetrazene 13 is cleaved by [2 + 2 + 2] cycloreversion. The methoxymethyl-substituted compound 8 exhibits a more complex cleavage pattern.