The anthraquinone process, which is still used, was developed during the 1930s by the German chemical manufacturer IG Farben in Ludwigshafen. It was first commercialized in 1908 in Weißenstein, Carinthia, Austria. The discovery of the synthesis of hydrogen peroxide by electrolysis with sulfuric acid introduced the more efficient electrochemical method. The first plant producing hydrogen peroxide was built in 1873 in Berlin. The bleaching effect of peroxides and their salts on natural dyes had been known since Thénard's experiments in in the 1820s, but early attempts of industrial production of peroxides failed. This process was used from the end of the 19th century until the middle of the 20th century. Īn improved version of Thénard's process used hydrochloric acid, followed by addition of sulfuric acid to precipitate the barium sulfate byproduct. This could cause personal injury if the difference is not properly understood by the user. Today, the term "oxygenated water" may appear on retail packaging referring to mixtures containing either water and hydrogen peroxide or water and dissolved oxygen. Nineteen years later Louis Jacques Thénard recognized that this compound could be used for the preparation of a previously unknown compound, which he described as eau oxygénée ("oxygenated water") – subsequently known as hydrogen peroxide. Structurally, the analogues all adopt similar skewed structures, due to repulsion between adjacent lone pairs.Īlexander von Humboldt is sometimes said to have been the first to report the first synthetic peroxide, barium peroxide, in 1799 as a by-product of his attempts to decompose air, although this is disputed due to von Humboldt's ambiguous wording. Diphosphane and hydrogen disulfide exhibit only weak hydrogen bonding and have little chemical similarity to hydrogen peroxide. Its melting point is also fairly high, being comparable to that of hydrazine and water, with only hydroxylamine crystallising significantly more readily, indicative of particularly strong hydrogen bonding.
It has the highest (theoretical) boiling point of this series (X = O, S, N, P). Hydrogen peroxide has several structural analogues with H mX−XH n bonding arrangements (water also shown for comparison). Density of aqueous solution of H 2O 2 H 2O 2 ( w/w).Dotted lines separate solid–liquid phases from solid–solid phases. Phase diagram of H 2O 2 and water: Area above blue line is liquid. This boiling point is 14 ☌ greater than that of pure water and 36.2 ☌ less than that of pure hydrogen peroxide. The boiling point of the same mixtures is also depressed in relation with the mean of both boiling points (125.1 ☌).
Hydrogen peroxide and water form a eutectic mixture, exhibiting freezing-point depression down as low as -56 ☌ pure water has a freezing point of 0 ☌ and pure hydrogen peroxide of -0.43 ☌. In aqueous solutions, hydrogen peroxide differs from the pure substance due to the effects of hydrogen bonding between water and hydrogen peroxide molecules. Crystals of H 2O 2 are tetragonal with the space group D 4Ĥ or P4 12 12. This difference is attributed to the effects of hydrogen bonding, which is absent in the gaseous state.
The molecular structures of gaseous and crystalline H 2O 2 are significantly different. It has been proposed that the enantiospecific interactions of one rather than the other may have led to amplification of one enantiomeric form of ribonucleic acids and therefore an origin of homochirality in an RNA world. It is the smallest and simplest molecule to exhibit enantiomerism. The approximately 100° dihedral angle between the two O–H bonds makes the molecule chiral. For comparison, the rotational barrier for ethane is 1040 cm −1 (12.4 kJ/mol). These barriers are proposed to be due to repulsion between the lone pairs of the adjacent oxygen atoms and dipolar effects between the two O–H bonds. Although the O−O bond is a single bond, the molecule has a relatively high rotational barrier of 386 cm −1 (4.62 kJ/ mol) for rotation between enantiomers via the trans configuration, and 2460 cm −1 (29.4 kJ/mol) via the cis configuration. Hydrogen peroxide ( H 2O 2) is a nonplanar molecule with (twisted) C 2 symmetry this was first shown by Paul-Antoine Giguère in 1950 using infrared spectroscopy. Structure and dimensions of H 2O 2 in the solid (crystalline) phase