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The same name (methylidene) was used for the distinct molecule , also known as
In organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...
, a methylidene group is any part of a molecule that consists of two hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
atoms bound
Bound or bounds may refer to:
Mathematics
* Bound variable
* Upper and lower bounds, observed limits of mathematical functions
Physics
* Bound state, a particle that has a tendency to remain localized in one or more regions of space
Geography
*B ...
to a carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...
atom, which is connected to the remainder of the molecule by a double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
. The group may be represented as , where the '=' denotes the double bond.
This stands in contrast to methylene, the group, which is connected to the rest of the molecule by two single bonds The distinction is often important, because the double bond is chemically different from two single bonds.
The same name (methylidene) was used for the distinct molecule , also known as carbene
In organic chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The general formula is or where the R represents substituents or hydrogen atoms.
The term "carbene" ma ...
. Formerly the methylene name was used for all three isomers (methylene, methylidene, and carbene).
Many organic compounds are named and classified as if they were the result of substituting a methylidene group for two adjacent hydrogen atoms of some parent molecule (even if they are not actually obtained that way). Thus, for example, methylenecyclopropene is named after cyclopropene
Cyclopropene is an organic compound with the formula . It is the simplest cycloalkene. Because the ring is highly strained, cyclopropene is difficult to prepare and highly reactive. This colorless gas has been the subject for many fundamental st ...
.
See also
*Methylene (compound)
Methylene (systematically named methylidene and dihydridocarbon; also called carbene) is an organic compound with the chemical formula (also written ). It is a colourless gas that fluoresces in the mid-infrared range, and only persists in dilut ...
* Methylene group
In organic chemistry, 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. The group may be represented as , where the '< ...
* Methyl group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...
* Methine
In organic chemistry, a methine group or methine bridge is a trivalent functional group , derived formally from methane. It consists of a carbon atom bound by two single covalent bond, bonds and one double bond, where one of the single bonds is t ...
References
Alkanediyl groups Functional groups {{organic-chem-stub