This article is about the functional group. For the compound, see Methylene (compound).
Chemical group (–CH₂–)
The hexamethylene diamine molecule contains six methylene groups
A methylene group is any part of a molecule that consists of two hydrogen atoms bound to a carbon atom, which is connected to the remainder of the molecule by two single bonds.[1] The group may be represented as −CH2− or >CH2, where the '>' denotes the two bonds.
This stands in contrast to a situation where the carbon atom is bound to the rest of the molecule by a double bond, which is preferably called a methylidene group, represented =CH2.[2] Formerly the methylene name was used for both isomers. The name “methylene bridge“ can be used for the single-bonded isomer, to emphatically exclude methylidene. The distinction is often important, because the double bond is chemically different from two single bonds.
The methylene group should be distinguished from the CH2 molecule called carbene.[3] This was also formerly called methylene.
^"methylene (preferred IUPAC name" (PDF).
^"methylidene (preferred IUPAC name" (PDF).
^IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "carbenes". doi:10.1351/goldbook.C00806
A methylenegroup is any part of a molecule that consists of two hydrogen atoms bound to a carbon atom, which is connected to the remainder of the molecule...
Look up methylene in Wiktionary, the free dictionary. Methylene may refer to: Methylenegroup or methylene bridge (CH2< or equivalently -CH2-), a part...
In organic chemistry, a methylene bridge, methylene spacer, or methanediyl group is any part of a molecule with formula −CH2−; namely, a carbon atom bound...
Methylthioninium chloride, commonly called methylene blue, is a salt used as a dye and as a medication. As a medication, it is mainly used to treat methemoglobinemia...
R−CH2−C6H5. Benzyl features a benzene ring (C6H6) attached to a methylenegroup (−CH2−) group. In IUPAC nomenclature, the prefix benzyl refers to a C6H5CH2...
such as the HCH angle in a methylenegroup Rocking: a change in angle between a group of atoms, such as a methylenegroup and the rest of the molecule...
Methyl group −CH 3 Methylenegroup or methylidene =CH 2 Methylene bridge or methanediyl −CH 2− Methanetriyl group >CH− Methylylidyne group ≡C− "Methanylylidene...
Dichloromethane (DCM, methylene chloride, or methylene bichloride) is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid...
to alkenes. Most often, the Wittig reaction is used to introduce a methylenegroup using methylenetriphenylphosphorane (Ph3P=CH2). Using this reagent...
Methylene diphenyl diisocyanate (MDI) is an aromatic diisocyanate. Three isomers are common, varying by the positions of the isocyanate groups around the...
groups are even more acidic because the carbonyl groups help stabilize the carbanion resulting from the removal of a proton from the methylenegroup between...
forms methylene arenium ion 3 with (based on X-ray crystallography) positive charge located in aromatic para position and with the methylenegroup 6° out...
Peligot, after determining methanol's chemical structure, introduced "methylene" from the Greek μέθυ (methy) "wine" and ὕλη (hȳlē) "wood, patch of trees"...
alkoxides, reactions of ethylene oxide with compounds containing active methylenegroup leads to the formation of butyrolactones: Ethylene oxide enters into...
ethenylidenes have the connectivity =C=CH2. Vinylene group, −CH=CH− Methylenegroup, −CH2− Vinyl group, −CH=CH2 Barry M. Trost; Andrew McClory "Metal Vinylidenes...
(CH2)2O2CH2. It is related to tetrahydrofuran (THF) by replacement of the methylenegroup (CH2) at the 2-position with an oxygen atom. The corresponding saturated...
such as aluminium chloride: C6H5CH2Cl + C6H6 → (C6H5)2CH2 + HCl The methylenegroup in diphenylmethane is mildly acidic with a pKa of 32.2, and so can...
4-bromo-3-oxobutanoyl bromide (2) leads to the amide (3). The active methylenegroup in that product is then nitrosated with sodium nitrite; the initial...
(called moieties). It can be traced back to the old name of methanol, "methylene" (from Ancient Greek: μέθυ méthu, 'wine' and ὕλη húlē, 'wood', 'forest')...
characterized by the shortening of a chain or ring by the removal of a methylenegroup or substitution of one or more methyl side chains by hydrogen atoms...
methylenegroup at Cβ. Glycine has only a hydrogen atom for its side chain, with a much smaller van der Waals radius than the CH3, CH2, or CH group that...
functional and pharmacologically active substances. It contains an acidic methylenegroup, flanked by both the nitrile and carbonyl, and so can be used in condensation...
the Clemmensen reduction, a method for converting a carbonyl group into a methylenegroup. Erik Christian Clemmensen was born on August 12, 1876, in Odense...
2-rearrangement. Consequently, the methylenegroup α- to the carboxyl group in the product is the methylenegroup from the diazomethane reagent. The 1...
chemical compound with the formula C6H12O: a cycloheptane in which one methylenegroup is replaced by oxygen. Oxepane can be polymerized by cationic initiators...
in which the amino group, NH2, is separated from the carboxyl group, COOH by a single methylenegroup, CH2. When the carboxyl group is deprotonated the...
The Riley oxidation is a selenium dioxide-mediated oxidation of methylenegroups adjacent to carbonyls. It was first reported by Riley and co-workers in...
all four atoms of a CH3 methyl group explicitly (or all three atoms of CH2 methylenegroup), one represents the whole group with one pseudo-atom. It must...
Global Information