Electronic Structure Studies of Tetrazolium-Based Ionic Liquids

New energetic ionic liquids are investigated as potential high energy density materials. Ionic liquids are composed of large, charge-diffuse cations, coupled with various usually oxygen containing anions. In this work, calculations have been performed on the tetrazolium cation with a variety of substituents. Density functional theory DFT with the B3LYP functional, using the 6-311Gd,p basis set was used to optimize geometries. Improved treatment of dynamic electron correlation was obtained using second order perturbation theory MP2. Heats of formation of the cation with different substituent groups were calculated using isodesmic reactions and Gaussian-2 calculations on the reactants. The cation was paired with oxygen rich anions CIO4-, NO3-, or NNO22- and those structures were optimized using both DFT and MP2. The reaction pathway for proton transfer from the cation to the anion was investigated.