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 to two hydrogen atoms and connected by single bonds to two other distinct atoms in the rest of the molecule. It is the repeating unit in the skeleton of the unbranched alkanes.
A methylene bridge is often called a methylene group or simply methylene, as in "methylene chloride" (dichloromethaneCH 2Cl 2). As a bridge in other compounds, for example in cyclic compounds, it is given the name methano. However, the term methylene group (or "methylidene") properly applies to the CH 2 group when it is connected to the rest of the molecule by a double bond (=CH2), giving it chemical properties very distinct from those of a bridging CH 2 group.
methylene, bridge, organic, chemistry, methylene, bridge, methylene, spacer, methanediyl, group, part, molecule, with, formula, namely, carbon, atom, bound, hydrogen, atoms, connected, single, bonds, other, distinct, atoms, rest, molecule, repeating, unit, ske. 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 to two hydrogen atoms and connected by single bonds to two other distinct atoms in the rest of the molecule It is the repeating unit in the skeleton of the unbranched alkanes The methylene bridge methanediyl group A methylene bridge can also act as a bidentate ligand joining two metals in a coordination compound such as titanium and aluminum in Tebbe s reagent 1 A methylene bridge is often called a methylene group or simply methylene as in methylene chloride dichloromethane CH2 Cl2 As a bridge in other compounds for example in cyclic compounds it is given the name methano However the term methylene group or methylidene properly applies to the CH2 group when it is connected to the rest of the molecule by a double bond CH2 giving it chemical properties very distinct from those of a bridging CH2 group Contents 1 Reactions 2 Examples 3 See also 4 ReferencesReactions EditCompounds possessing a methylene bridge located between two strong electron withdrawing groups such as nitro carbonyl or nitrile groups are sometimes called active methylene compounds 2 Treatment of these with strong bases can form enolates or carbanions which are often used in organic synthesis Examples include the Knoevenagel condensation and the malonic ester synthesis 3 Examples EditExamples of compounds which contain methylene bridges include Malonic acid Acetylacetone MalononitrileSee also EditMethyl group Methylene group MethyneReferences Edit W A Herrmann 1982 The methylene bridge In Advances in Organometallic Chemistry volume 20 pages 195 197 Active methylene compound House Herbert O 1972 Modern Synthetic Reactions Menlo Park CA W A Benjamin ISBN 0 8053 4501 9 This chemistry related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Methylene bridge amp oldid 1097424421, wikipedia, wiki, book, books, library,
