Trihydrogen oxide is a predicted inorganic compound of

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

and

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

with the chemical formula . This is still a

hypothetical compound A hypothetical chemical compound is a chemical compound that has been conceived of, but is not known to have been synthesized, observed, or isolated (identified or shown to exist). Some hypothetical compounds cannot form at all, due to steric ef ...

, one of the unstable hydrogen polyoxides. It is hypothesized that the compound could constitute a thin layer of metallic liquid around the cores of

Uranus Uranus is the seventh planet from the Sun. It is a gaseous cyan-coloured ice giant. Most of the planet is made of water, ammonia, and methane in a Supercritical fluid, supercritical phase of matter, which astronomy calls "ice" or Volatile ( ...

and

Neptune Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

, and that this could be the source of their magnetic fields. Calculations indicate the stability of in solid, superionic, and fluid metallic states at the deep interior conditions of these planets.

Synthesis

Trihydrogen oxide has not been observed experimentally as of 2023, but its existence is predicted by calculation using the CALYPSO method. The compound should be stable in the pressure range 450–600 GPa and could be produced by the reaction: ::

Physical properties

The compound is considered not a true molecular ''trihydrogen oxide'' compound. Instead, each oxygen atom is linked by a strong (covalent) bond to only two hydrogen atoms, as a

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

molecule, and there are molecules of

dihydrogen Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest and most abundant chemical element in the universe, constituting about 75% of all normal matter. Under standard conditions, hydrogen is a gas of diatom ...

inserted in the voids of the water molecules network. Structurally, it is thus a stoichiometric combination. At 600 GPa and 7000 K, the compound density is calculated to be 4.3 g/cm³. Molecular dynamics simulations were carried out at constant density for different temperatures: * At 1000 K, is an

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic Lattice (group), lattices result from stretching a cubic crystal system, cubic lattice along two of its orthogonal pairs by two different factors, res ...

crystalline solid (space group ''Cmca''). * At 1250 K, this solid passes into a superionic state. * The compound liquefies at 5250 K, and the liquid should have metallic-like electrical conductivity.

In the Solar System

The magnetic fields of both Uranus and Neptune are special—non-dipolar and non-axisymmetric. This fact can be explained if the magnetic fields are produced by dynamo effect within a sufficiently thin conductive layer. However, the origin of the fields is still problematic because the cores of these planets are probably solid (thus too rigid), and the thick mantles of ice are too poorly conductive to create the effect.

References

{{Hydrides by group Inorganic compounds Oxides Polyoxides Oxoacids Hypothetical chemical compounds Theoretical chemistry