Solvent_Mediated_Synthesis

Inorganic Ozonides

Inorganic ozonides are compounds containing the radical anion O3, a 19-valence- electron anion, showing a conspicuous red color. Due to extreme air-, moisture- and temperature sensitivity, gram amounts of pure alkali ozonides have been synthesized not until 1985, starting from alkali hyperoxides and ozone.[1] This procedure permits the synthesis of the higher alkali ozonides (K – Cs), the starting materials of any further ozonide chemistry.[2]
All other ozonide compounds require other/new synthesis routes e.g. metathesis reactions[3] or ion exchange.[4]
An ozonide crystal sealed in a capillary.[3] An ozonide crystal sealed in a capillary.[3]

Meanwhile, the field of ozonides has been expanded to:
  • alkaline-earth metals
    Cs2Ba(O3)4•2NH3[5] and Sr(O3)2•9NH3[6]
  • several organic cations and bications
    e.g. (NMe4)O3 (see figure right),[3], (PMe4)O3[7], (Me3N(CH2)3NMe3)(O3)2[8]
  • ozonides, soluble in organic solvents
    e.g. (Bu4N)O3[9], Rb([18]crown-6)O3•NH3[10]
Structure of Tetramethylammoniumozonid

Recent results:
Picture of a single rod The reaction of [12]crown-4 with CsO3 in liquid ammonia yields this compound.
Left: The prominent structural feature are 1{Cs8(O3)10}2- rods which are arranged in a tetragonal rod packing (see below).
The structural confinement enforced by the small crown ether molecules lead to remarkably short intermolecular O⋅⋅⋅O distances indicated by the dotted red line in the figure above. Picture of the rod packing

A recent review:

References:

For more information please contact Hanne Nuss.

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