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Methylene – Species and Group

As a reactive species, a methylene refers to an electron-deficient carbene, represented as :CH2. 

Carbenes are carbon-containing electrophiles that contain only 6 valence electrons instead of the standard eight required for stability. It has an unshared electron pair and two bonds, making it a divalent species, highly unstable, having a fleeting existence. Though classified as electrophiles, methylene species have no formal charge and are neutral.

 

 

As a group, methylene refers to the -CH2- unit of a carbon chain in organic compounds. It is a divalent group and forms part of the carbon backbone of hydrocarbons. It can also be found next to various functional groups, as part of the central carbon chain. 

For example, a methylene group occupies a central position when part of hydrocarbon propane (CH3-CH2-CH3) or when the methylene group is attached to any functional group, like in the case of propanal (CH3-CH2-CHO). 

It is part of a repeating unit of a polymer chain, in the case of polyethene. 

Repeating methylene units can add nonpolarity in molecules.

 

 

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Atom

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Bonding In Atoms

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Covalent Bond

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Electronic Displacement in a Covalent Bond

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Common Types of Reactions

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Drawing Organic Structures

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Functional Groups in Organic Chemistry

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Reactive Intermediates

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Stereoisomerism - Conformation and Configurational Isomerism

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