Lead oxychlorides are

halide In chemistry, a halide (rarely halogenide) is a binary chemical compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative (or more electropositive) than the halogen, to make a fluor ...

compounds of

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

with the general formula PbClO(H).

Occurrence in nature

Lead oxychlorides are found naturally in the minerals hereroite as Pb₃₂O₂₁2Cl₁₀, in rickturnerite as Pb₇O₄(OH)Cl₃, in vladkrivovichevite as Pb₃₂O₁₈Cl₁₄, in asisite as Pb₇SiO₄O₄Cl₂, in damaraite as Pb₃Cl(OH)O₂, in hereroite as Pb₃Cl(OH)O₂, in

Mendipite Mendipite is a rare mineral that was named in 1939 for the locality where it is found, the Mendip Hills in Somerset, England. It is an oxyhalide of lead with formula Pb3Cl2O2. Crystal structure Most references assert that mendipite crystallis ...

as Pb₃Cl₂O₂, and in the

dimorph In materials science, polymorphism describes the existence of a solid material in more than one form or crystal structure. Polymorphism is a form of isomerism. Any crystalline material can exhibit the phenomenon. Allotropy refers to polymorphism ...

minerals

laurionite Laurionite (PbCl(OH)) is a lead halide mineral. It forms colorless to white crystals in the orthorhombic crystal system and is dimorphous with paralaurionite, both members of the matlockite group. It was first described in 1887 for an occurren ...

and

paralaurionite Paralaurionite is a colorless mineral consisting of a basic lead chloride PbCl(OH) that is dimorphous with laurionite. It is a member of the matlockite group. The name is derived from para-, the Greek for "near", and laurionite, because of its po ...

, which are PbCl(OH) members of the

matlockite Matlockite is a rare lead halide mineral, named after the town of Matlock in Derbyshire, England, where it was first discovered in a nearby mine. Matlockite (chemical formula: PbFCl) gives its name to the matlockite group which consists of rare ...

group.

Usage

Historically, the primary use of lead oxychlorides was in a mixture with other lead compounds (e.g.

lead carbonate Lead(II) carbonate is the chemical compound with the chemical formula . It is a white solid with several practical uses, despite its toxicity. It occurs naturally as the mineral cerussite. Structure Like all metal carbonates, lead(II) carbonate a ...

white lead White lead is the basic lead carbonate 2PbCO3·Pb(OH)2. It is a complex salt, containing both carbonate and hydroxide ions. White lead occurs naturally as a mineral, in which context it is known as hydrocerussite, a hydrate of cerussite. It was ...

") as a pigment in

lead paint Lead paint or lead-based paint is paint containing lead. As pigment, lead(II) chromate (, "chrome yellow"), lead(II,IV) oxide, (, "red lead"), and lead(II) carbonate (, "white lead") are the most common forms.. Lead is added to paint to acceler ...

s. The lead compounds were first fused, and the product then ground to fine powder. The powder was then suspended in

drying oil A drying oil is an oil that hardens to a tough, solid film after a period of exposure to air, at room temperature. The oil hardens through a chemical reaction in which the components crosslink (and hence, polymerize) by the action of oxygen (not ...

s (e.g. linseed), to produce e.g. Pattinson's white (PbCl₂ 2Pb(OH)₂) or Turner's yellow (PbCl₂ 5-7PbO). Turner's yellow is also known as Patent yellow, Cassel yellow, Montpelier yellow, Kassler yellow, mineral yellow, and Verona yellow. In the late 19th century, lead oxychlorides were briefly used in the manufacture of electrodes for lead-acid batteries. Patented by

Charles Francis Brush Charles Francis Brush (March 17, 1849 – June 15, 1929) was an American engineer, inventor, entrepreneur, and philanthropist. Biography Brush was born in Euclid Township, Ohio to Isaac Elbert Brush and Delia Williams Phillips. Isaac Brush ...

in 1876, the depressions in a ribbed or grooved sheet of lead were filled with pulverized lead oxychloride (later also

lead sulfate Lead(II) sulfate (PbSO4) is a white solid, which appears white in microcrystalline form. It is also known as ''fast white'', ''milk white'', ''sulfuric acid lead salt'' or ''anglesite''. It is often seen in the plates/electrodes of car batteries, ...

). In a second step, the grooved sheet was covered with paper and horizontally suspended in a salt or acid solution, to which a zinc plate was then also added. The mixture in the grooved sheet's depressions was then electrolytically reduced to sponge lead, forming a functional lead-acid cell electrode (if subsequently used as a positive electrode, the sponge lead was converted to

lead peroxide Lead(IV) oxide is the inorganic compound with the formula PbO2. It is an oxide where lead is in an oxidation state of +4. It is a dark-brown solid which is insoluble in water. It exists in two crystalline forms. It has several important applicat ...

during the cell's initial "formation" charge). Brush's technique was superseded by the now standard

Faure Faure is an Occitan family name meaning blacksmith, from Latin ''faber''. It is pronounced differently from the accented surname Fauré, as in Gabriel Fauré, French composer and organist. People Politicians * Dominique Faure (born 1959), Fre ...

pasting method in 1880.

References

{{reflist Lead compounds