Magnesium oxide Magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of and consists of a lattice of Mg ions and O ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + HO → Mg(OH)), but it can be reversed by heating it to separate moisture. Magnesium oxide was historically known as magnesia alba (literally, the white mineral from magnesia – other sources give magnesia alba as MgCO), to differentiate it from "magnesia
Dihydrogen complex variety of related complexes such as Cr(H)(CO) and [Fe(H)(H)(dppe)]. Kubas et al.'s findings also led to a reevaluation of previously described compounds. For example, the complex "RuH(PPh)" described in 1968 was reformulated as a dihydrogen complex. Dihydrogen complex Dihydrogen complexes are coordination complexes containing intact H as a ligand. The prototypical complex is W(CO)(PCy)(H). This class of compounds represent intermediates in metal-catalyzed reactions involving hydrogen. Hundreds of dihydrogen complexes have been reported. Most examples are cationic transition metals complexes with octahedral geometry. Upon complexation, the H−H bond is extended to 0.81–0.82 Å as indicated by neutron diffraction, about a 10%