Sodium dihydrogen arsenate pyroarsenate salt NaHAsO. 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
Dihydrogen bond a normal N−H vibration whereas the lower energy band is assigned to the same bond, which is interacting with the B−H. Upon dilution of the solution, the 3300 cm band increased in intensity and the 3210 cm band decreased, indicative of intermolecular association. Interest in dihydrogen bonding was reignited upon the crystallographic characterization of the molecule HNBH. In this molecule, like the one studied by Brown and Hazeltine, the hydrogen atoms on nitrogen have a partial positive charge, denoted H, and the hydrogen atoms on boron have a partial negative charge, often denoted H. In other words, the amine is