A trioxide is a compound with three oxygen atoms. For metals with the M<sub>2</sub>O<sub>3</sub> formula there are several common structures. Al<sub>2</sub>O<sub>3</sub>, Cr<sub>2</sub>O<sub>3</sub>, Fe<sub>2</sub>O<sub>3</sub>, and V<sub>2</sub>O<sub>3</sub> adopt the corundum structure. Many rare earth oxides adopt the "A-type rare earth structure" which is hexagonal. Several others plus indium oxide adopt the "C-type rare earth structure", also called "bixbyite", which is cubic and related to the fluorite structure.

List of trioxides

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MO<sub>3</sub>

  • Carbon trioxide, CO<sub>3</sub>
  • Chromium trioxide, CrO<sub>3</sub>
  • Molybdenum trioxide, MoO<sub>3</sub>
  • Rhenium trioxide, ReO<sub>3</sub>
  • Selenium trioxide, SeO<sub>3</sub>
  • Sulfur trioxide, SO<sub>3</sub>
  • Tellurium trioxide, TeO<sub>3</sub>
  • Tungsten trioxide, WO<sub>3</sub>
  • Uranium trioxide, UO<sub>3</sub>
  • Xenon trioxide, XeO<sub>3</sub>

M<sub>2</sub>O<sub>3</sub>

  • Antimony trioxide, Sb<sub>2</sub>O<sub>3</sub>
  • Arsenic trioxide, As<sub>2</sub>O<sub>3</sub>
  • Bismuth(III) oxide, Bi<sub>2</sub>O<sub>3</sub>
  • Boron trioxide, B<sub>2</sub>O<sub>3</sub>
  • Cobalt(III) oxide, Co<sub>2</sub>O<sub>3</sub>
  • Dichlorine trioxide, Cl<sub>2</sub>O<sub>3</sub>
  • Dinitrogen trioxide, N<sub>2</sub>O<sub>3</sub>
  • Gadolinium oxide, Gd<sub>2</sub>O<sub>3</sub>
  • Gallium(III) oxide, Ga<sub>2</sub>O<sub>3</sub>
  • Gold trioxide, Au<sub>2</sub>O<sub>3</sub>
  • Indium(III) oxide, In<sub>2</sub>O<sub>3</sub>
  • Iron(III) oxide, Fe<sub>2</sub>O<sub>3</sub>
  • Manganese(III) oxide, Mn<sub>2</sub>O<sub>3</sub>
  • Nickel(III) oxide, Ni<sub>2</sub>O<sub>3</sub>
  • Phosphorus trioxide, P<sub>4</sub>O<sub>6</sub> (named before the true formula known)
  • Thallium(III) oxide, Tl<sub>2</sub>O<sub>3</sub>
  • Terbium(III) oxide, Tb<sub>2</sub>O<sub>3</sub>
  • Trioxidane, H<sub>2</sub>O<sub>3</sub>
  • Vanadium trioxide, V<sub>2</sub>O<sub>3</sub>
  • Ytterbium(III) oxide, Yb<sub>2</sub>O<sub>3</sub>
  • Yttrium(III) oxide, Y<sub>2</sub>O<sub>3</sub>

Other trioxides

  • Mineral trioxide aggregate
  • Sulfur trioxide pyridine complex, SO<sub>3</sub>(py)

References