anthracene9yl

Anthracene-9-yl is the aryl substituent derived from anthracene by removal of a hydrogen atom at the 9-position, producing a reactive aryl radical used as a building block in organic synthesis and materials science. The 9-yl designation indicates attachment at the central carbon of the three fused benzene rings.

The 9-position lies at the center of the anthracene molecule, one of the two central carbons shared by all three rings. The resulting anthracene-9-yl fragment preserves a highly conjugated, planar polycyclic framework, with the radical center stabilized by delocalization across the three rings.

In practice, anthracene-9-yl groups are introduced through reactions that generate or preserve the 9-yl site, such as cross-coupling or radical couplings using anthracene derivatives or precursors. The ease of forming the 9-yl radical depends on substituents and reaction conditions.

Applications include use as a conjugated building block in organic electronics and photonics, notably in organic light-emitting diodes (OLEDs), organic photovoltaics, and field-effect transistors, where the extended π-system of the anthracene-9-yl moiety can tune energy levels and optical properties.

Nomenclature: the term "anthracene-9-yl" indicates attachment at carbon 9; a common synonym is 9-anthryl.