Methylenden
Methylenden is not a standard term in current chemical nomenclature. In English-language chemistry literature it may appear as a misspelling or informal shorthand for methylidene-related motifs, or as a reference to compounds bearing the methylidene moiety. The more precise term is methylidene (often written methylen- in systematic names).
The methylidene group is a divalent substituent with the formula =CH2. It is typically exocyclic to a
In synthesis and analysis, the methylidene unit is introduced or manipulated through various methylenation strategies. Common
Related concepts include methylene (the divalent –CH2– linkage inside molecules) and various naming forms such as