CHCH2

CHCH2 is a condensed structural formula used in organic chemistry to denote a two‑carbon hydrocarbon fragment, consisting of a CH unit connected to a CH2 unit. It is not a discrete molecule with its own set of properties; rather, it serves as a substructure that can appear within larger molecules or in reaction-mechanism diagrams. The notation conveys connectivity and hydrogen counts without drawing a full structural diagram.

In practice, CHCH2 may be written to indicate a specific segment of a molecule such as a CH–CH2 linkage. If a radical or charge is involved, the fragment can be shown with radical or ionic notation, for example •CH–CH2 or CH–CH2•, to indicate the location of an unpaired electron or a charge. In many contexts, the fragment is treated as sp3‑hybridized, but the exact geometry depends on the surrounding molecular framework.

Common contexts for CHCH2 include reaction mechanisms, radical polymerization end groups, or fragmentation patterns in mass spectrometry where such fragments help infer chain length and connectivity of alkyl segments. The fragment may represent a portion of an alkyl chain or other two‑carbon linkage, depending on the larger structure being described.

Note that CHCH2 is not a standalone chemical entity with separate physical properties; its significance lies in illustrating how a particular two‑carbon unit connects within a larger system. See also condensed structural formula, radical notation, alkyl group, and fragmentation in mass spectrometry.