An inorganic compound is typically a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

that lacks carbon–hydrogen bonds⁠that is, a compound that is not an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''. Inorganic compounds comprise most of the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

, although the compositions of the deep mantle remain active areas of investigation. All allotropes (structurally different pure forms of an element) and some simple

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

compounds are often considered inorganic. Examples include the allotropes of carbon (

graphite Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable ...

diamond Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of e ...

, buckminsterfullerene, graphene, etc.),

carbon monoxide Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

, carbides, and salts of inorganic anions such as

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

s, cyanides, cyanates, thiocyanates,

isothiocyanate In organic chemistry, isothiocyanate is a functional group as found in compounds with the formula . Isothiocyanates are the more common isomers of thiocyanates, which have the formula . Occurrence Many isothiocyanates from plants are produce ...

s, etc. Many of these are normal parts of mostly organic systems, including

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s; describing a chemical as inorganic does not necessarily mean that it cannot occur within living things.

History

Friedrich Wöhler's conversion of

ammonium cyanate Ammonium cyanate is an inorganic compound with the formula . It is a colorless, solid salt. Structure and reactions The structure of this salt was verified by X-ray crystallography. The respective C–O and C–N distances are 1.174(8) and 1.192 ...

into

urea Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two Amine, amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest am ...

in 1828 is often cited as the starting point of modern

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

. In Wöhler's era, there was widespread belief that

s were characterized by a vital spirit. In the absence of vitalism, the distinction between inorganic and organic chemistry is merely semantic.

Modern usage

* The

Inorganic Crystal Structure Database Inorganic Crystal Structure Database (ICSD) is a chemical database founded in 1978 by Günter Bergerhoff at the University of Bonn in Germany and I. D. Brown at McMaster University in Canada. It is now produced by FIZ Karlsruhe in Europe and t ...

(ICSD) in its definition of "inorganic" carbon compounds, states that such compounds may contain ''either'' C-H or C-C bonds, but not both. * The book series ''

Inorganic Syntheses ''Inorganic Syntheses'' is a book series which aims to publish "detailed and foolproof" procedures for the synthesis of inorganic compounds.IUPAC The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...

does not offer a definition of "inorganic" or "inorganic compound" but does define inorganic polymer as "...skeletal structure that does not include carbon atoms."

References

{{Authority control *

History

Modern usage

See also

References