Preparation, characterization, and x-ray structure analysis of 1,4-diazabicyclo-2,2,2-octane (DABCO) and ammonium cation with tetrathiomolybdate anion

The reaction of H2S gas with an aqueous solution of ammonium heptamolybdate in the presence of 1,4-diazabicyclo-2,2,2-octane (DABCO) led to the formation of a red colored complex. The complex was recrystallized in hot water and characterized by elemental analysis and UV-Visible, FT-IR, and 1H NMR spectroscopy. The single sharp peak in the 1H NMR spectrum has revealed that all the methylene protons are equivalent due to the hydrogen resonating between the two nitrogens in the DABCO cation. The complex crystallizes in a cubic system with space group P213, a = 10.9482(9) Å, α = 90°, V = 1325.3(7) Å3, R 1 = 0.0154, wR 2 = 0.038, Z = 4. The structure consists of the tetrahedral tetrathiomolybdate anions, which form an extended three-dimensional network in the solid state involving Mo-S...H-N hydrogen bonding interactions with DABCO and the ammonium cation. © 2004 Springer Science+Business Media, Inc.