An inorganic compound is typically a
chemical compound 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
carbonates,
cyanides,
cyanates,
thiocyanates,
isothiocyanates, 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 into
urea 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
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 ...
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 (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'' does not define inorganic compounds. The majority of its content deals with metal complexes of organic ligands.
*
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."
See also
*
Inorganic compounds by element
*
List of inorganic compounds
*
List of named inorganic compounds
*
Mineral acid
References
{{Authority control
*