HYDROGEN ION

The name hydrogen ion is recommended by IUPAC as a general name for all ions of hydrogen and its isotopes.

Depending on the charge of the ion, two different classes can be distiguished:

Cation (positively charged)

When hydrogen loses its electron, the following [cation|cations] can be formed

• Hydron: general name refering to the positive ion of any hydrogen isotope (H⁺)
• Proton: ¹H⁺
• Deuteron: ²H⁺, D⁺
• Triton: ³H⁺, T⁺

In addition, the ions produced by the reaction of these cations with water as well as their hydrates are called hydrogen ions:

• Oxoniumion: H₃O⁺
• Zundel cation: H₅O₂⁺
• Eigen cation: H₉O₄⁺

In connection with acids, hydrogen ions typically refer to hydrons.

Anion (negatively charged)

Hydrogen anions are formed when additional electrons are taken on:

• Hydride: general name referring to the negative ion of any hydrogen isotope
• Deuteride: ²H^-, D^-
• Tritide: ³H^-, T^-

References

• Compendium of Chemical Terminology, 2nd edition

McNaught, A.D. and Wilkinson, A. Blackwell Science, 1997 [ISBN 0-86542-6848], also online