Organic chemistry

Organic chemistry is the scientific study of the structure, properties, composition, reactions, and synthesis of organic compounds that by definition contain carbon. Organic compounds are composed of carbon and hydrogen, and may contain any number of other elements. Organic compounds often contain nitrogen, oxygen, phosphorus or sulphur.

History

Organic chemistry as a science is generally agreed to have started in 1828 with Friedrich Woehler's synthesis of the organic, biologically significant compound urea by accidentally evaporating an aqueous solution of ammonium cyanate NH₄OCN. The name organic chemistry comes from the idea that carbon chains were only produced by living things or organisms. This has been proven false, but remains the reason why organic chemistry is close in name to the word organism.

Characteristics of organic substances

Organic compounds are covalently bonded and thus, its bonds are directional. 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 (catenation). In contrast to inorganic materials, organic compounds typically melt, sublime, or decompose below 300°C. Neutral organic compounds tend to be less soluble in water compared to many inorganic salts, with the exception of certain compounds such as ionic organic compounds and low molecular weight alcohols and carboxylic acids where there is hydrogen bonding present. Organic compounds tend to be much more soluble in organic solvents such as ether or alcohol, but the solubility in each solute is dependent on the functional groups present and of the general structure.

Organic nomenclature

Organic nomenclature is the system established for naming and grouping organic compounds.

Aliphatic compounds

Aliphatic compounds are organic molecules that do not contain aromatic systems. Typically, they contain hydrocarbon chains.

Hydrocarbons - Alkanes - Alkenes - Dienes or Alkadienes - Alkynes - Haloalkanes

Aromatic compounds

Aromatic compounds are organic molecules that contain one or more aromatic ring system.

Benzene - Toluene - Styrene - Xylene - Aniline - Phenol - Acetophenone - Benzonitrile - Haloarenes - Naphthalene - Anthracene - Phenanthrene - Benzopyrene - Coronene - Azulene - Biphenyl

Heterocyclic compounds

Heterocyclic compounds are cyclic organic molecules whose ring(s) contain at least one heteroatom. These heteroatoms can include oxygen, nitrogen, phosphorus, and sulfur.

Imidazole - Indole - Pyridine - Pyrrole - Thiophene - Furan - Purines

Functional groups

Alcohols - Aldehydes - Alicyclic compounds - Amides - Amines - Carbohydrates - Carboxylic acids - Esters - Ethers - Ketones - Lipids - Mercaptans - Nitriles

Polymers

Polymers are a special kind of molecule. Generally considered "large" molecules, polymers get their reputation regarding size because they are molecules that consist of multiple smaller segments. The segments could be chemically identical, which would make such a molecule a homopolymer. Or the segments could vary in chemical structure, which would make that molecule a heteropolymer. Polymers are a subset of "macromolecules" which is just a classification for all molecules that are considered large.

Polymers can be organic or inorganic. Commonly-encountered polymers are usually organic (e.g., polyethylene, polypropylene, Plexiglass, etc.). But inorganic polymers (e.g., silicone) are also familiar to everyday items.

Important biological molecules such as proteins, nucleic acids and polysaccharides are also polymers (biopolymers).

Determining the molecular structure of an organic compound

Currently, there exist several methods for characterizing an organic compound. In general usage are (in alphabetical order):

Crystallography: This is the most precise method; 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: Chiefly used to determine the presence (or absence) of certain functional groups.
Mass spectrometry: Used to determine the molecular weight of a compound and the fragmentation pattern.
Nuclear magnetic resonance (NMR) spectrometry
UV/VIS spectroscopy: Used to determine degree of conjugation in the system

See Analytical chemistry for additional methods.

Organic reactions

Most of the time spent in an introductory organic chemistry class involves learning the processes used to manufacture organic molecules. For details, see Organic reaction

External links

{{{1}}} ISBN {{{2}}}

af:Organiese chemie ar:كيمياء عضوية bg:Органична химия ca:Química orgànica da:Organisk kemi de:Organische Chemie el:Οργανική χημεία es:Química orgánica eo:Organika kemio fa:شیمی آلی fr:Chimie organique gl:Química Orgánica ko:유기화학 hr:Organska kemija id:Kimia organik it:Chimica organica la:Chemica Organica lv:Organiskā ķīmija lb:Organesch Chimie hu:Szerves kémia ms:Kimia organik mn:Органик хими nl:Organische chemie ja:有機化学 no:Organisk kjemi nn:Organisk kjemi pl:Chemia organiczna pt:Química orgânica ro:Chimie organică ru:Органическая химия simple:Organic chemistry sl:Organska kemija sr:Органска хемија su:Kimia organik fi:Orgaaninen kemia sv:Organisk kemi vi:Hóa hữu cơ uk:Органічна хімія zh:有机化学