NEW IONIC OZONIDES - SYNTHESES, STRUCTURES, AND PROPERTIES OF N(CH3)4O3 AND N(C2H5)4O3

In contrast to the known alkali-metal ozonides, tetraalkylammonium ozonides can not be synthesized by reaction of ozone with the respective hyperoxides due to the oxidizability of the cation. Therefore, N(CH3)4O3 and N(C2H5)4O3 have been synthesized via a new route by double reaction of their hyperoxides with alkali-metal ozonides in liquid ammonia. N(CH3)4O3 crystallizes in the orthorhombic space group Pmmn (No. 59) with a = 850.96 (25) pm, b = 689.95 (32) pm, c = 544.39 (16) pm, and Z = 2. N(C2H5)4O3 crystallizes in the trigonal space group P3(1)21 (No. 152) with a = 706.60 (15) pm, c = 1752.60 (43) pm, and Z = 3. Diffraction data were collected on an Enraf-Nonius CAD4 diffractometer using Mo K-alpha radiation. Whereas the structure of N(CH3)4O3 shows a relationship with the CsCl type of structure, atomic arrangement in the N(C2H5)4O3 structure derives from the NaCl type of structure. C-H...O hydrogen bonds were found in both structures and were also evidenced by IR investigations. The decomposition of these two compounds has been studied by mass spectroscopy and DTA/TG methods. Two different mechanisms of decomposition, caused by the absence or the presence of beta-hydrogen atoms, are observed for N(CH3)4O3 and N(C2H5)4O3. N(CH3)4O3 is surprisingly stable, only decomposing above 75-degrees-C. As a consequence of their higher solubilities in commonly used solvents (e.g. acetonitrile), these new ozonides are of interest in developing a preparative chemistry involving ionic ozonides.