Sodium dihydrogen arsenate Sodium dihydrogen arsenate Sodium dihydrogen arsenate is the inorganic compound with the formula NaHAsO. Related salts are also called sodium arsenate, including NaHAsO (disodium hydrogen arsenate) and NaHAsO (sodium dihydrogen arsenate). Sodium dihydrogen arsenate is a colorless solid that is highly toxic. The salt is the conjugate base of arsenic acid: In the laboratory, it is prepared in this way, crystallizing from a hot saturated aqueous solution, where it is highly soluble when hot (75.3 g in 100 mL at 100 °C). It is obtained as the monohydrate. Upon heating, solid NaHAsOHO, loses water of crystallization and converts to the
Dihydrogen complex some cases, hydrogen ligands are usefully characterized by X-ray crystallography, but often the presence of metals, which strongly scatter X-rays, complicates the analysis. The triangular MH subunit has six normal modes of vibration, one of which is mainly of ν character. In free H, this very strong bond absorbs at 4300 cm, whereas in dihydrogen complexes the frequency drops to around 2800 cm. Two preparation methods involve the direct reactions with H gas. The first entails the addition of H to an unsaturated metal center, as originally reported for W(CO)(P-i-Pr)(H). In such cases, the unsaturated complex in fact features an