As part of a series of reports of highly nitrated molecules that may serve as new high energy materials, here we report on various nitrated derivatives of 3,6-dihydro-1,2,4,5-tetrazine. The parent molecule is one of the smallest ringed systems with two isolated azo groups (–NN–) as part of the cycle. With only two carbon atoms in the structures, the amount of carbon-containing substances released upon decomposition is minimized, making these compounds more “green”. Density functional theoretical calculations show a decreasing trend in energy of decomposition with increasing nitro group content, although the specific enthalpies of decomposition are commensurate with other currently-used materials.