Lead Oxide Powder - PbO

Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula PbO. PbO occurs in two polymorphs, one litharge having a tetragonal crystal structure and the other massicot having an orthorhombic crystal structure. Modern applications for PbO are mostly in lead-based industrial glass and industrial ceramics, including computer components.

As determined by X-ray crystallography, both polymorphs, tetragonal and orthorhombic feature a pyramidal four-coordinate Pb center. In the tetragonal form the four Pb-O bonds have the same length, but in the orthorhombic two are shorter and two longer. The pyramidal nature indicates the presence of a stereo-chemically active lone pair of electrons.When PbO occurs in tetragonal lattice structure it is called litharge; and when the PbO has orthorhombic lattice structure it is called massicot. The PbO can be changed from massicot to litharge or vice versa by controlled heating and cooling.The tetragonal form is usually red or orange color, while the orthorhombic is usually yellow or orange, but the color is not a very reliable indicator of the structure.The tetragonal and orthorhombic forms of PbO occur naturally as rare minerals.