CH3CH2CH2

CH3CH2CH2 is the shorthand notation for the n-propyl group, a straight-chain alkyl substituent derived from propane by removing one hydrogen from the terminal carbon. In IUPAC terms, the substituent is propan-1-yl, often called n-propyl. The neutral substituent form is written as CH3CH2CH2−, while the radical form is CH3CH2CH2•. The parent hydrocarbon for this group is propane, with the formula C3H8.

Structure and nomenclature

The group consists of three carbon atoms arranged in a linear chain: CH3–CH2–CH2–, with attachment occurring at the end carbon. This distinguishes it from the propan-2-yl (isopropyl) group, which attaches through the central carbon. In SMILES notation, the n-propyl substituent is represented as CCC when used as a fragment of a larger molecule.

Occurrence and uses

The n-propyl group is a common alkyl substituent in organic synthesis. It is used to extend carbon frameworks and to modify physical properties of compounds (such as boiling point and solubility). Propyl groups appear in a wide range of derivatives, including esters, ethers, amines, and hydrocarbons. They can be introduced via alkylation reactions or through the use of propyl-containing reagents such as propyl halides or propyl Grignard reagents.

Properties and considerations

As a substituent, the n-propyl group does not correspond to a standalone pure compound; its properties are tied to the parent molecule. The related isopropyl group (propan-2-yl) is a constitutional isomer with different reactivity and steric characteristics. Safety and handling depend on the overall compound, but hydrocarbon alkyl groups typically contribute to flammability and hydrocarbon-like behavior.

See also

Propyl group, propan-2-yl, propane, alkyl substituents.