Trimethylamine N-oxide Trimethylamine N-oxide Trimethylamine "N"-oxide (TMAO) is an organic compound with the formula (CH)NO. It is in the class of amine oxides. Although the anhydrous compound is known, trimethylamine "N"-oxide is usually encountered as the dihydrate. It is a product of the oxidation of trimethylamine, a common metabolite in animals. Both the anhydrous and hydrated materials are white, water-soluble solids. Trimethylamine "N"-oxide is an osmolyte found in saltwater fishes, sharks, rays, molluscs, and crustaceans. It is considered as a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea
Dihydrogen bond a protic acid and the borane end is hydridic. The resulting B−HH−N attractions stabilize the molecule as a solid. In contrast, the related substance ethane, HCCH, is a gas with a boiling point 285 °C lower. Because two hydrogen centers are involved, the interaction is termed a dihydrogen bond. Formation of a dihydrogen bond is assumed to precede formation of H from the reaction of a hydride and a protic acid. A very short dihydrogen bond is observed in NaBH·2HO with H−H contacts of 1.79, 1.86, and 1.94 Å. Protonation of transition metal hydride complexes is generally thought to occur