See Also

Organic chemistry

Organic chemistry is a specific discipline within the subject of chemistry Chemistry

Chemistry is the science [i] of matter [i] at the atom [i]ic to molecular [i] scale, dealing primarily ... 

. It is the scientific Science

Science in the broadest sense refers to any system of knowledge attained by verifiable means.... 

 study of the structure, properties, composition, reactions Chemical reaction

A chemical reaction is a process that results in the interconversion of chemical substance [i]s . ... 

, and preparation of chemical compounds of carbon Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

 and hydrogen Hydrogen

|- | Triple point [i] || 13.8033 K, 7.042 kPa ... 

, which may contain any number of other elements, such as nitrogen Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

, oxygen Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8. ... 

, halogens Halogen

The halogens are a chemical series [i]. ... 

, and more rarely phosphorus Phosphorus

|- | Critical temperature [i] || 994 K [i] ... 

 or sulfur Sulfur

Sulfur or sulphur is the chemical element [i] in the periodic table [i] that has the symbol S' ... 

  . The original definition of organic chemistry came from the misperception that these compounds were always related to life processes, but now it is known that life also depends heavily on inorganic chemistry Inorganic chemistry

Inorganic chemistry is the branch of chemistry [i] concerned with the properties and behavior of inorganic compound [i] ... 

; for example, many enzymes rely on transition metals such as iron and copper; and materials such as shells, teeth and bones are part organic, part inorganic in composition.

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Encyclopedia

Organic chemistry is a specific discipline within the subject of chemistry Chemistry

Chemistry is the science [i] of matter [i] at the atom [i]ic to molecular [i] scale, dealing primarily ... 

. It is the scientific Science

Science in the broadest sense refers to any system of knowledge attained by verifiable means.... 

 study of the structure, properties, composition, reactions Chemical reaction

A chemical reaction is a process that results in the interconversion of chemical substance [i]s . ... 

, and preparation of chemical compounds of carbon Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

 and hydrogen Hydrogen

|-
| Triple point [i] || 13.8033 K, 7.042 kPa
... 

, which may contain any number of other elements, such as nitrogen Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

, oxygen Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8.... 

, halogens Halogen

The halogens are a chemical series [i]. ... 

, and more rarely phosphorus Phosphorus

|-
| Critical temperature [i] || 994 K [i]
... 

 or sulfur Sulfur

Sulfur or sulphur is the chemical element [i] in the periodic table [i] that has the symbol S' ... 

  .

The original definition of organic chemistry came from the misperception that these compounds were always related to life processes, but now it is known that life also depends heavily on inorganic chemistry Inorganic chemistry

Inorganic chemistry is the branch of chemistry [i] concerned with the properties and behavior of inorganic compound [i] ... 

; for example, many enzymes rely on transition metals such as iron and copper; and materials such as shells, teeth and bones are part organic, part inorganic in composition. Inorganic chemistry deals, apart from elemental carbon, only with simple carbon compounds, with molecular structures which do not contain carbon to carbon connections . This does not mean that single-carbon organic compounds do not exist . Compounds that are related to life processes are dealt with in the branch of chemistry which is called biochemistry Biochemistry

Biochemistry is the study of the chemical processes and chemical transformations in living organism [i]s ... 

.

Because of their unique properties, multi-carbon compounds exhibit extremely large variety and the range of application of organic compounds is enormous. They form the basis of or are important constituents of many products and of course they form the basis of all life processes.

The different shapes and chemical reactivities of organic molecules provide an astonishing variety of functions, like those of enzyme Enzyme

Enzymes are protein [i]s that accelerate, or catalyze [i], chemical reaction [i]s. ... 

 catalyst Catalyst

In chemistry, a catalyst is a substance [i] that decreases the activation energy [i] ... 

s in biochemical reactions of live systems. The autopropagating nature of these is what life is all about.

Because of the special properties of carbon, it is likely that life on other star Star

A star is a massive, compact body of plasma [i] in outer space [i] that is held together by its ... 

 systems will be found to be carbon-based, in spite of speculations about the possibility of substituting silicon Silicon

Silicon is the chemical element [i] in the periodic table [i] that has the symbol Si and atomic number [i] ... 

, which lies just below carbon in the periodic table.

Trends in organic chemistry include chiral synthesis Chiral synthesis

Chiral synthesis also called asymmetric synthesis or enantioselective synthesis is organic synthesis [i] ... 

, green chemistry Green chemistry

Green chemistry is the design of chemical products and processes that reduce or eliminate the use and ge... 

, microwave chemistry, fullerene Fullerene

The fullerenes are a recently-discovered family of carbon [i] allotropes [i] named... 

s and microwave spectroscopy.

Historic highlights



Towards the beginning of the nineteenth century, chemists generally thought that compounds from living organisms were too complicated in structure and that these compounds, through a 'vital force' or vitalism Vitalism

Vitalism, as defined by the Merriam-Webster dictionary, is
... 

, were unique in that they could self-propagate. They named these compounds 'organic' and proceeded to ignore them.

Organic chemistry received a boost when it was realized that these compounds could be treated in ways similar to inorganic compounds and could be manufactured by means other than 'vital force'. Around 1816 Michel Chevreuil started a study of soaps made from various fat Fat

Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely ins... 

s and alkali. He separated the different acids that, in combination with the alkali, produced the soap. Since these were all individual compounds, he demonstrated that it was possible to make a chemical change in various fats , producing new compounds, without 'vital force'.

The real event that has completely destroyed the myth of 'vitalism' occurred, however, when in 1828 Friedrich Wöhler Friedrich Wöhler

Friedrich Whler was a German [i] chemist [i], best-known for his synthesis of urea [i], but als ... 

 first manufactured the organic chemical urea Urea

Urea is an organic compound [i] of carbon [i], nitrogen [i], oxygen [i] and hydrogen [i], with the formula [i] ... 

 , a constituent of the liquid waste matter urine from the inorganic ammonium cyanate NH4OCN, in what is now called the Wöhler synthesis.

A great next step was when in 1856 William Henry Perkin William Perkin

Sir William Henry Perkin was an English [i] chemist best known for his discovery, at the age of ... 

, while trying to manufacture quinine Quinine

Quinine is a natural white crystal [i]line alkaloid [i] having antipyretic [i], anti-malarial [i] ... 

, again accidentally came to manufacture the organic dye now called Perkin's mauve Mauveine

References

External links

[i]
... 

, which by generating a huge amount of money greatly increased interest in organic chemistry. Another step was the laboratory preparation of DDT DDT

DDT was the first modern pesticide [i] and is arguably the best known organic pesticide. ... 

 by Othmer Zeidler in 1874, but the insecticide properties of this compound were not discovered till much later.

The history of organic chemistry continues with the discovery of petroleum Petroleum

Petroleum or crude oil is a black, dark brown or greenish liquid [i] found in porous rock formati ... 

 and its separation into fractions according to boiling ranges. The conversion of different compound types or individual compounds by various chemical processes created the petroleum chemistry leading to the birth of the petrochemical industry, which successfully manufactured artificial rubbers, the various organic adhesives, the property modifying petroleum additives, and plastics.

The pharmaceutical industry began in the last decade of the 19th century when acetyl-salicilic acid manufacture was started in Germany by Bayer Bayer

Bayer AG [i] is a German [i] chemical [i] and pharmaceutical [i] ... 

.

Biochemistry Biochemistry

Biochemistry is the study of the chemical processes and chemical transformations in living organism [i]s ... 

, the chemistry of living organisms, their structure and interactions in vitro and inside living systems, has only started in the 20th century, opening up a brand new chapter of organic chemistry with enormous scope.

Classification of organic substances


Description and nomenclature

Classification is not possible without having a full description of the individual compounds.
In contrast with inorganic chemistry Inorganic chemistry

Inorganic chemistry is the branch of chemistry [i] concerned with the properties and behavior of inorganic compound [i] ... 

, in which describing a chemical compound could be achieved by simply enumerating the chemical symbols of the elements Chemical element

A chemical element, often called simply an element, is a substance [i] that can... 

 present in the compound together with the number of these elements in the molecule, in organic chemistry the relative arrangement of the atoms within a molecule has to be added for a full description.

One way of describing the molecule is by drawing its structural formula Structural formula

The structural formula of a chemical compound [i] is a graphical representation of the molecular structu ... 

. Because of the complexity this method has changed, becoming simplified over the years. The latest version is the line formula, which achieves simplicity without introducing ambiguity, whilst representing carbon and hydrogen by implication. The disadvantage which arises from the fact that structural formulae cannot be described by words, and that they are not easily printable does not arise when the structure is described by the organic nomenclature IUPAC nomenclature of organic chemistry

The IUPAC nomenclature of organic chemistry is a systematic [i] way of naming organic chemical compound [i] ... 

 .

Because of the difficulty due to the very large number and variety of organic compounds, chemists realized early on that the establishment of an internationally accepted system of naming organic compounds was of paramount importance. The Geneva Nomenclature was born in 1892 as a result of a number of international meetings on the subject.

It was also realized that as the family of organic compounds grew, the system would have to be expanded and modified. This task was ultimately taken on by the International Union on Pure and Applied Chemistry, IUPAC International Union of Pure and Applied Chemistry

The International Union of Pure and Applied Chemistry is an international non-governmental organization [i] ... 

.

Recognizing the fact that in the branch of Biochemistry, the complexity of organic structures increases, the IUPAC organisation joined forces with IUBMB, the International Union of Biochemistry and Molecular Biology, to produce a list of joint recommendations on nomenclature.

Further on, as number and complexity grew, new recommendations were made within IUPAC for simplification. The first such recommendation was presented in 1951 when a cyclic benzene structure was named a cyclophane Cyclophane

A cyclophane is a hydrocarbon [i] consisting of an aromatic [i] unit and an aliphatic [i] chain [i] that ... 

. Later recommendations extended the method to the simplification of other complex cyclic structures, including for instance heterocyclics as well, and named such structures phanes.

For ordinary communication, to spare a tedious description, the official IUPAC naming recommendations are not always followed in practice except when it is necessary to give a concise definition to a compound, or when the IUPAC name is simpler . Otherwise the common or trivial name may be used, often derived from the source of the compound.

Classification

In summary: organic substances are classified by their molecular structural arrangement and by what other atoms are present with the chief constituent in their makeup, whilst in a structural formula, hydrogen is implicitly assumed to occupy all free valencies of an appropriate carbon atom, which remain after accounting for branching, other element and/or multiple bonding.
Hydrocarbons and Functional Groups
Classification normally starts with the hydrocarbons Hydrocarbon

[i] that consists only of the elements [[carbon]... 

: compounds which contain only carbon and hydrogen. For sub-classes see below. Other elements, present themselves in atomic configurations called functional groups Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

 which have decisive influence on the chemical and physical characteristics of the compound; thus those containing the same atomic formations have similar characteristics, which may be miscibility with water, acidity/ alkalinity, chemical reactivity, oxidation Redox

Redox reactions include all chemical processes [i] in which atoms have their oxidation number [i] ... 

 resistance, or others. Some functional groups are also radicals, similar to those in inorganic chemistry, defined as atomic configurations which pass during chemical reactions from one chemical compound into another without change.

Some of the elements of the functional groups may stand alone and the group name is not strictly appropriate, but because of their decisive effect on the way they modify the characteristics of the hydrocarbons in which they are present they are classed with the functional groups, and their specific effect on the properties lends excellent means for characterisation and classification.

Referring to the hydrocarbon types below, many, if not all of the functional groups Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

 which are typically present within aliphatic compounds are also represented within the aromatic Aromaticity

Aromaticity is a chemical property in which a conjugated [i] ring of unsaturated bonds ... 

 and alicyclic Alicyclic compound

An alicyclic compound is an organic compound [i] that is both aliphatic [i] and cyclic. ... 

 group of compounds, unless they are dehydrated, which would lead to non-reacting co-optional groups.

Reference is made here again to the organic nomenclature IUPAC nomenclature of organic chemistry

The IUPAC nomenclature of organic chemistry is a systematic [i] way of naming organic chemical compound [i] ... 

, which shows an extensive number of classes of compounds according to the presence of various functional groups, based on the IUPAC International Union of Pure and Applied Chemistry

The International Union of Pure and Applied Chemistry is an international non-governmental organization [i] ... 

 recommendations, but also some based on trivial names. Putting compounds in sub-classes becomes more difficult when more than one functional group is present.

Two overarching chain type categories exist: Open Chain aliphatic compounds and Closed Chain cyclic compounds. Those in which both open chain and cyclic parts are present are normally classed with the latter.
Aliphatic compounds
The aliphatic hydrocarbons are subdivided into three groups, homologous series according to their state of saturation: paraffins alkane Alkane

An alkane is an acyclic saturated [i] hydrocarbon [i]. ... 

s without any double or triple bonds, olefins alkene Alkene

In organic chemistry [i], an alkene, olefin, or olefine is an unsaturated [i] chemical compound [i] ... 

s with double bonds, which can be mono-olefins with a single double bond, di-olefins, or di-enes with two, or poly-olefins with more. The third group with a triple bond is named after the name of the shortest member of the homologue series as the acetylenes alkyne Alkyne

Alkynes are hydrocarbon [i]s that have at least one triple bond [i] between two carbon [i] atoms. ... 

s. The rest of the group is classed according to the functional groups present.

From another aspect aliphatics can be straight chain or branched chain compounds, and the degree of branching also affects characteristics, like octane number Octane rating

The octane rating is a measure of the autoignition [i] resistance of gasoline [i] and other fuels used i ... 

 or cetane number in petroleum chemistry.
Aromatic and alicyclic compounds
Cyclic compounds can, again, be saturated or unsaturated. Because of the bonding angle of carbon, the most stable configuration of the cyclic compounds contain six carbon atoms, but rings with five carbon atoms are also frequent, others are rarer. The cyclic hydrocarbons divide into alicyclic Alicyclic compound

An alicyclic compound is an organic compound [i] that is both aliphatic [i] and cyclic. ... 

s and aromatic Aromaticity

Aromaticity is a chemical property in which a conjugated [i] ring of unsaturated bonds ... 

s also called arenes.

Of the alicyclic Alicyclic compound

An alicyclic compound is an organic compound [i] that is both aliphatic [i] and cyclic. ... 

 compounds the cycloalkane Cycloalkane

Cycloalkanes are chemical compound [i]s with a one or more rings of carbon [i]s to which hydrogen [i]s a ... 

s do not contain double bonds, whilst cycloalkenes do. The simplest member of the cycloalkane family is cyclopropane Cyclopropane

Cyclopropane is a cycloalkane [i] molecule [i] with the molecular formula C3H6 consisting of three carbon [i] ... 

. A notable group amongst the alicyclics is represented by the terpene Terpene

Terpenes are a large and varied class of hydrocarbons [i], produced primarily by a wide variety of plant ... 

s.

What is different in aromatic Aromaticity

Aromaticity is a chemical property in which a conjugated [i] ring of unsaturated bonds ... 

 hydrocarbons is that they contain conjugated or alternating double bonds. One of the simplest example of this is benzene Benzene

Benzene, also known as benzol, is an organic [i] chemical compound [i] with the ... 

 the structure of which was formulated by Kekulé who first proposed the delocalization Delocalized electron

In physics delocalized electrons are electron [i]s in a molecule [i] that are not associated with a sing ... 

 or resonance principle for explaining its structure.

The characteristics of the cyclic hydrocarbons are again altered if there are functional groups present, but additionally here some of the elements which are classed with the functional groups can form part of the ring itself. The compounds which only have carbon and hydrogen in their ring are also called homocyclic, those with other elements in the ring heterocyclic Heterocyclic compound

Heterocyclic compounds are organic compounds [i] that contain a ring structure contain ... 

 and the atom substituting the carbon is a heteroatom.

The heteroatom of heterocyclic molecules is generally O,S, or N, but most often nitrogen, and the heterocyclics of live systems are compounds with nitrogen. Examples of groups among the heterocyclics are the aniline dye Aniline

Aniline, phenylamine or aminobenzene is an organic compound with the formula C [i]6H [i] ... 

s, the great majority of the compounds discussed in biochemistry Biochemistry

Biochemistry is the study of the chemical processes and chemical transformations in living organism [i]s ... 

 such as alkaloid Alkaloid

An alkaloid, strictly speaking, is a naturally-occurring amine [i] produced by a plant [i], but amines p ... 

s, many compounds related to vitamin Vitamin

Vitamins are nutrient [i]s required for essential metabolic reactions in the body . ... 

s, steroid Steroid

A steroid is a lipid [i] characterized by a carbon [i] skeleton with four fused rings. ... 

s, nucleic acid Nucleic acid

A nucleic acid is a complex, high-molecular-weight biochemical [i] macromolecule [i] compos ... 

s and also numerous medicines. Constructionally simple representatives of the group are pyrrole Pyrrole

Pyrrole, or pyrrol, is a heterocyclic [i] aromatic [i] organic compound [i], a five-membered ring ... 

  and indole Indole

Indole is an aromatic [i] heterocyclic [i] organic compound [i]. ... 

 .
Polymers
One important property of carbon in organic chemistry is that it can form certain compounds, the individual molecules of which are capable of attaching themselves to one another, thereby forming a chain or a network. The process is called polymerisation and the chains or networks polymers Polymer

Polymer is a term used to describe molecule [i]s consisting of structural unit [i]s and a large number o ... 

, whilst the source compound is a monomer. Two main groups of polymers exist: those artificially manufactured are referred to as industrial polymers Plastic

Plastic covers a range of synthetic or semisynthetic polymerization [i] products. ... 

 
or synthetic polymers Polymer

Polymer is a term used to describe molecule [i]s consisting of structural unit [i]s and a large number o ... 

 and those naturally occurring as biopolymers.

Since the invention of the first artificial polymer, bakelite Bakelite

Bakelite is a brand name [i]d material based on the thermosetting [i] phenol formaldehyde resin [i] ... 

, the family has quickly grown with the invention of others. Common synthetic organic polymers are polyethylene Polyethylene

Polyethylene or polyethene is a thermoplastic [i] commodity heavily used in consumer products. ... 

 or polythene, polypropylene Polypropylene

Polypropylene or polypropene is a thermoplastic [i] polymer [i], used in a wide variety of applica ... 

, nylon Nylon

Nylon [i] represents a family of synthetic polymer [i]s, a thermoplastic [i] material, fir ... 

, teflon Polytetrafluoroethylene

Polytetrafluoroethylene is a fluoropolymer [i] discovered by Roy J. Plunkett [i] of DuPont [i] in 1938 [i] ... 

 or PTFE, polystyrene Polystyrene

Polystyrene is a polymer [i] made from the monomer [i] styrene [i], a liquid [i] hydrocarbon [i] that is ... 

, polyester Polyester

Polyester is a category of polymer [i]s, or, more specifically condensation polymer [i]s, which contain ... 

s, polymethylmethacrylate Acrylic glass

Polymethyl methacrylate or poly(methyl 2-methylpropenoate) is the synthetic polymer [i] of methyl methacrylate [i] ... 

  polyvinylchloride Polyvinyl chloride

Polyvinyl chloride, commonly abbreviated PVC, is a widely-used plastic [i]. ... 

 or PVC, and polyisobutylene  important artificial or synthetic rubber Rubber

Rubber is an elastic hydrocarbon [i] polymer [i] which occurs as a milky emulsion [i] in the sap of se ... 

 also the polymerised butadiene 1,3-Butadiene

1,3-Butadiene is a simple conjugated [i] diene [i]. ... 

, a rubber component.

The examples are generic terms, and many varieties of each of these may exist, with their physical characteristics fine tuned for a specific use. Changing the conditions of polymerisation changes the chemical composition of the product by altering chain length, or branching, or the tacticity Tacticity

Tacticity is the relative stereochemistry [i] of adjacent chiral [i] centers within a macromolecule [i]... 

. With a single monomer as a start the product is a homopolymer. Further, secondary component may be added to create a heteropolymer  and the degree of clustering of the different components can also be controlled. Physical characteristics, such as hardness, density, mechanical or tensile strength Tensile strength

Tensile strength measures the force required to pull something such as rope, wire, or a structural beam ... 

, abrasion resistance, heat resistance, transparency, colour, etc. will depend on the final composition.

The only other element that can produce polymers is silicon. The silicones Silicone

Silicones, or polysiloxanes, are inorganic-organic polymer [i]s with the chemical formula [R2SiO]n ... 

, however, show one major difference from carbon based polymers, inasmuch as unlike the direct C-C bonds of those based on carbon in silicones the Si atoms are joined indirectly through oxygen links.
Biomolecules
Biomolecular chemistry Biomolecule

A biomolecule is a chemical compound [i] that naturally occurs in living organisms. ... 

 is a major category within organic chemistry. Many complex multi-functional group molecules are important in living organisms. Some are long-chain biopolymers. The main classes are carbohydrate Carbohydrate

Carbohydrates are chemical compound [i]s that contain oxygen [i], hydrogen [i], and carbon [i] atom [i]s ... 

s, amino acid Amino acid

In chemistry [i], an amino acid is any molecule [i] that contains both amine [i] and carboxyl [i] functional group [i] ... 

s and protein Protein

Proteins are large organic compound [i]s made of amino acid [i]s arranged in a linear chain and joined b ... 

s, polysaccharides, lipid Lipid

Lipids are a class of hydrocarbon [i]-containing organic compound [i]s essential for the structure and f ... 

s, and nucleic acid Nucleic acid

A nucleic acid is a complex, high-molecular-weight biochemical [i] macromolecule [i] compos ... 

s.
Others
Organic compounds containing bonds of carbon to nitrogen, oxygen and the halogens are not normally grouped separately. Others are sometimes put into major groups within organic chemistry and discussed under titles such as organosulfur chemistry Organosulfur compounds

Organosulfur compounds are organic compound [i]s containing sulfur [i]. ... 

, organometallic chemistry, organophosphorus chemistry Organophosphorus

Organophosphorus compounds are chemical compound [i]s containing carbon [i]-phosphorus [i] bonds [i] ... 

 and organosilicon chemistry Organosilicon

Organosilicon compounds are chemical compound [i]s containing carbon [i] silicon [i] bonds [i] ... 

.

Characteristics of organic substances

Organic compounds are generally covalently bonded Covalent bond

Covalent bonding is an intramolecular form of chemical bond [i]ing characterized by the sharing of one o ... 

. This allows for unique structures such as long carbon chains and rings. The reason carbon is excellent at forming unique structures and that there are so many carbon compounds is that carbon atoms form very stable covalent bonds with one another . In contrast to inorganic materials, organic compounds typically melt, boil, sublimate, or decompose below 300°C. Neutral organic compounds tend to be less soluble in water Water

Water is a taste [i]less, odor [i]less substance that is essential to all known forms of life [i] and i ... 

 compared to many inorganic salts Salt

In chemistry [i], a salt is any ionic compound [i] composed of cation [i]s and anion [i]s so that the ... 

, with the exception of certain compounds such as ionic organic compounds and low molecular weight alcohols Alcohol

In chemistry [i], an alcohol is any organic compound [i] in which a hydroxyl [i] group [i] ... 

 and carboxylic acids Carboxylic acid

Carboxylic acids are organic acid [i]s characterized by the presence of a carboxyl group, which ha ... 

 where hydrogen bonding Hydrogen bond

In chemistry [i], a hydrogen bond is a type of attractive intermolecular force [i] that exists between t ... 

 occurs.

Organic compounds tend rather to dissolve in organic solvents which are either pure substances like ether Diethyl ether

Diethyl ether, also known as ether and ethoxyethane, is a clear, colorless, and highly flam... 

 or ethyl alcohol Ethanol

This article is about the chemical compound.... 

, or mixtures, such as the paraffinic solvents such as the various petroleum ethers and white spirits, or the range of pure or mixed aromatic solvents obtained from petroleum or tar fractions by physical separation or by chemical conversion. Solubility in the different solvents depends upon the solvent type and on the functional groups Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

 if present. Solutions are studied by the science of Physical Chemistry. Like inorganic salts, organic compounds may also form crystal Crystal

In chemistry [i] and mineralogy [i], a crystal is a solid [i] in which the constituent atom [i]s, molecule [i] ... 

s. Unique property of carbon in organic compound Organic compound

An organic compound is any member of a large class of chemical compound [i]s whose molecule [i]s contain ... 

s is that its valency does not always have to be taken up by atoms of other elements, and when it is not, a condition termed unsaturation results. In such cases we talk about carbon carbon double bonds Covalent bond

Covalent bonding is an intramolecular form of chemical bond [i]ing characterized by the sharing of one o ... 

 or triple bonds Alkyne

Alkynes are hydrocarbon [i]s that have at least one triple bond [i] between two carbon [i] atoms. ... 

. Double bonds alternating with single in a chain are called conjugated Conjugated system

A chemically conjugated system is a system of atoms covalent [i]ly bonded [i] with alterna ... 

 double bonds. An aromatic Aromaticity

Aromaticity is a chemical property in which a conjugated [i] ring of unsaturated bonds ... 

 structure is a special case in which the conjugated chain is a closed ring.

Molecular structure elucidation

Organic compounds Organic compound

An organic compound is any member of a large class of chemical compound [i]s whose molecule [i]s contain ... 

 consist of carbon atoms, hydrogen atoms, and functional groups Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

. The valence of carbon is 4, and hydrogen is 1, functional groups are generally 1. From the number of carbon atoms and hydrogen atoms in a molecule the degree of unsaturation can be obtained. Many, but not all structures can be envisioned by the simple valence rule that there will be one bond for each valence number. The knowledge of the chemical formula Chemical formula

A chemical formula is a concise way of expressing information about the atom [i]s that constitute a par ... 

 for an organic compound is not sufficient information because many isomer Isomer

In chemistry [i], isomers are molecule [i]s with the same chemical formula [i] and often with the same k ... 

s can exist.
Organic compounds often exist as mixtures. Because many organic compounds have relatively low boiling points and/or dissolve easily in organic solvents there exist many methods for separating mixtures into pure constituents that are specific to organic chemistry such as distillation Distillation

Distillation is a method of separation [i] of substance [i]s based on differences in ... 

, crystallization Crystallization

Crystallization is the process of formation of solid crystal [i]s from a solution [i].... 

 and chromatography Chromatography

Chromatography is the collective term for a family of laboratory techniques [i] for the separation of mixtures [i] ... 

 techniques.
There exist several methods for deducing the structure an organic compound. In general usage are :

  • Crystallography: This is the most precise method for determining molecular geometry Molecular geometry

    Molecular geometry or molecular structure is the three dimensional [i] arrangement of th ... 

    ; however, it is very difficult to grow crystals of sufficient size and high quality to get a clear picture, so it remains a secondary form of analysis.
  • Elemental Analysis: A destructive method used to determine the elemental composition of a molecule.
  • Infrared spectroscopy Infrared spectroscopy

    Infrared spectroscopy is the subset of spectroscopy [i] that deals with the Infrared [i] part of the electromagnetic spectrum [i] ... 

    : Chiefly used to determine the presence of certain functional groups Functional group

    In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

    .
  • Mass spectrometry Mass spectrometry

    Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio [i] of ion [i]s. ... 

    : Used to determine the molecular weight of a compound and from the fragmentation pattern its structure.
  • Nuclear magnetic resonance spectrometry Nuclear magnetic resonance

    Nuclear magnetic resonance is a physical phenomenon based upon the magnetic [i] property of a... 

     identifies different nuclei from their chemical environment.
  • UV/VIS spectroscopy Ultraviolet-visible spectroscopy

    Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry involves the spectroscopy [i] ... 

    : Used to determine degree of conjugation in the system


Additional methods are provided by analytical chemistry.

Organic reactions

Organic reactions are chemical reaction Chemical reaction

A chemical reaction is a process that results in the interconversion of chemical substance [i]s . ... 

s involving organic compound Organic compound

An organic compound is any member of a large class of chemical compound [i]s whose molecule [i]s contain ... 

s. While pure hydrocarbon Hydrocarbon

[i] that consists only of the elements [[carbon]... 

s undergo certain limited classes of reactions, many more reactions which organic compounds undergo are largely determined by functional group Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

s. The general theory of these reactions involves careful analysis of such properties as the electron affinity of key atoms,bond strengths and steric hindrance. These issues can determine the relative stability of short-lived reactive intermediates, which usually directly determine the path of the reaction. An example of a common reaction is a substitution reaction written as:
Nu- + C-X → C-Nu + X-


where X is some functional group Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

 and Nu is a nucleophile Nucleophile

In chemistry [i], a nucleophile is a reagent [i] that forms a chemical bond [i] to its reaction partner ... 

.

There are many important aspects of a specific reaction. Whether it will occur spontaneously or not is determined by the Gibbs free energy change of the reaction. The heat that is either produced or needed by the reaction is found from the total Enthalpy Enthalpy

In thermodynamics [i], the quantity enthalpy, symbolized by H, also called heat content, is the ... 

 change. Other concerns include whether side reactions occur from the same reaction conditions. Any side reactions which occur typically produce undesired compounds which may be anywhere from very easy or very difficult to separate from the desired compound.

See also

  • Important publications in organic chemistry
  • List of organic reactions

References




External links


  • Journal of Organic Chemistry
  • Organic Letters



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