In chemistry, congeners are chemical substances "related to each other by origin, structure, or function".

Common origin and structure

Any significant quantity of a

polyhalogenated compound Polyhalogenated compounds (PHCs) are any compounds with multiple substitutions of halogens. They are of particular interest and importance because they bioaccumulate in humans, and comprise a superset of which has many toxic and carcinogenic indus ...

is by default a blend of multiple molecule types because each molecule forms independently, and chlorine and bromine do not strongly select which site(s) they bond to. *

Polychlorinated biphenyl Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act in 1979 and internationally by t ...

s (PCBs) are a family of 209 congeners. *

Polybrominated biphenyl Polybrominated biphenyls (PBBs), also called brominated biphenyls or polybromobiphenyls, are a group of manufactured chemicals that consist of polyhalogenated derivatives of a biphenyl core. Their chlorine analogs are the PCBs. While once widel ...

s and

polychlorinated diphenyl ethers Polychlorinated diphenyl ethers (PCDEs) are structurally similar to polychlorinated biphenyls (PCBs), both which may be toxic polyhalogenated compounds and some PCDE congeners have been reported to cause toxic responses similar to those caused by ...

are also families of 209 congeners. Similarly polychlorinated dibenzodioxins,

polychlorinated dibenzofurans More thorough treatise of all groups with similar actions and binding to aryl hydrocarbon receptor is given in Dioxins and dioxin-like compounds. Polychlorinated dibenzofurans (PCDFs) are a family of organic compounds with one or several of the ...

polychlorinated terphenyl Polychlorinated terphenyls (PCTs) are a group of chlorine derivatives of terphenyls. They are chemically related to polychlorinated biphenyls and have similar chemical properties. They have very low electrical conductivity, high heat stability ...

polychlorinated naphthalene Polychlorinated naphthalene (PCN) are the products obtained upon treatment of naphthalene with chlorine. The generic chemical formula is C10 H8−(m+n) Cl(m+n). Commercial PCNs are mixtures of up to 75 components and byproducts.van de Plassche, ...

polychloro phenoxy phenol Polychloro phenoxy phenols (polychlorinated phenoxy phenols, PCPPs) are a group of organic polyhalogenated compounds. Among them include triclosan Triclosan (sometimes abbreviated as TCS) is an antibacterial and antifungal agent present in s ...

, and

polybrominated diphenyl ethers Polybrominated diphenyl ethers or PBDEs, are a class of organobromine compounds that are used as flame retardants. Like other brominated flame retardants, PBDEs have been used in a wide array of products, including building materials, electronics, ...

(PBDEs) ( pentabromodiphenyl ether,

octabromodiphenyl ether Octabromodiphenyl ether (octaBDE, octa-BDE, OBDE, octa, octabromodiphenyl oxide, OBDPO) is a brominated flame retardant which belongs to the group of polybrominated diphenyl ethers (PBDEs). Composition, uses, and production Commercial octaBDE (al ...

, decabromodiphenyl ether), etc. are also groups of congeners.

Common origin

Congener (alcohol) In the alcoholic beverages industry, congeners are substances, other than the desired type of alcohol, ethanol, produced during fermentation. These substances include small amounts of chemicals such as methanol and other alcohols (known as fusel a ...

, substances other than alcohol (desirable or undesirable) also produced during fermentation. *Congeners of

oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omeg ...

s can modify

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

behavior, protecting against tumors or having effects on blood pressure.

Common structure

Congeners can refer to similar compounds that substitute other elements with similar valences, yielding molecules having similar

structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

. Examples: * potassium chloride and sodium chloride may be considered congeners; also potassium chloride and

potassium fluoride Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide and occurs naturally as the rare ...

. *

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

(HOOH),

hydrogen thioperoxide Hydrogen thioperoxide, also called oxadisulfane or sulfur hydride hydroxide, is the chemical with the structure H–S–O–H. It can be considered as the simple sulfur-substituted analog of the common hydrogen peroxide (H–O–O–H) chemical, a ...

(HSOH), and

hydrogen disulfide Hydrogen disulfide is the inorganic compound with the formula H2S2. This hydrogen chalcogenide is a pale yellow volatile liquid with a camphor-like odor. It decomposes readily to hydrogen sulfide (H2S) and elemental sulfur.R. Steudel "Inorgani ...

(HSSH). Structural analogs are often

isoelectronic Isoelectronicity is a phenomenon observed when two or more molecules have the same structure (positions and connectivities among atoms) and the same electronic configurations, but differ by what specific elements are at certain locations in th ...

Other

*Congeners refer to the various oxidation states of a given element in a compound. For example,

titanium(II) chloride Titanium(II) chloride is the chemical compound with the formula TiCl2. The black solid has been studied only moderately, probably because of its high reactivity. Ti(II) is a strong reducing agent: it has a high affinity for oxygen and reacts irre ...

(titanium dichloride),

titanium(III) chloride Titanium(III) chloride is the inorganic compound with the formula TiCl3. At least four distinct species have this formula; additionally hydrated derivatives are known. TiCl3 is one of the most common halides of titanium and is an important cataly ...

(titanium trichloride), and titanium(IV) chloride (

titanium tetrachloride Titanium tetrachloride is the inorganic compound with the formula . It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. is a volatile liquid. Upon contact with humid air, it forms thick clouds ...

) may be considered congeners. *Congeners can refer to other elements in the same group in the periodic table. For example, congeners of the Group 11 element

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

are

silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...

and

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

, sometimes found together in the same

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 Apr ...

s (

porphyry copper deposit Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Predating or associated with those fluids are vertical dikes of ...

) due to their chemical similarity.

References

Chemistry {{Chem-stub