Wasserstoff3

Wasserstoff3 is not a standard term in established chemistry. In German-language or speculative discussions, it may be used to refer to triatomic hydrogen (H3) in a general sense, or more commonly to the trihydrogen cation H3+. Because the neutral triatomic hydrogen is highly unstable and difficult to observe under ordinary conditions, most reliable discussions of Wasserstoff3 distinguish clearly between the neutral H3 species and the H3+ ion.

The H3+ cation is a well-known and experimentally established species in astrochemistry. It has an equilateral triangular geometry with D3h symmetry and forms in interstellar environments by the reaction H2 + H+ → H3+. H3+ is one of the most abundant molecular ions in diffuse and dense interstellar clouds and acts as a key proton donor in ion–molecule reactions, driving networks that lead to more complex molecules. Its infrared spectroscopy provides a diagnostic window into conditions such as temperature and ionization rate in space.

In contrast, the neutral triatomic hydrogen H3 would be a highly reactive radical with no permanent dipole moment in its likely symmetric forms, making it extremely short-lived and challenging to detect spectroscopically. The neutral species is predicted to be unstable under normal laboratory conditions, with observations limited to theoretical studies or transient high-energy environments.

In laboratory settings, H3+ is produced and studied in ion traps and plasmas, while the neutral H3 remains largely a theoretical or highly transient species. See also hydrogen, H3+, interstellar chemistry, and hydronium H3O+.