diameterene

Diameterene is a theoretical class of carbon-based nanostructures proposed to have a defined, tunable cross-sectional diameter built into their lattice geometry. The concept differs from conventional carbon nanotubes in that diameterene models emphasize discrete, prescribed diameters arising from specific arrangements of sp2-hybridized carbon rings, rather than a continuum of possible tube sizes.

In proposed models, diameterene structures may take cylindrical or quasi-cylindrical shapes with cross-sections defined by motifs from graphene derivatives. These designs often rely on curvature-inducing units or ring assemblies that enforce a stable, repeatable diameter. Theoretical work explores how such units can propagate along an axis to yield extended, tube-like nanostructures with well-controlled dimensions.

At present, diameterene remains theoretical. There is no confirmed experimental synthesis or characterization. Synthesis challenges include achieving defect-free curvature control, scalable assembly of the necessary ring motifs, and stabilization of the structure under ambient conditions. Researchers have discussed potential routes such as bottom-up chemical synthesis of curved polycyclic motifs, or guided self-assembly on templated substrates, but practical realization has not been demonstrated.

Predicted properties of diameterene materials are closely tied to their diameter and bonding topology. They are expected to exhibit high mechanical stiffness and thermal stability due to strong carbon–carbon bonds, with electronic behavior ranging from metallic to semiconducting depending on diameter and chirality. Optical properties would be influenced by pi-conjugation along the axis, potentially enabling unique photonic or sensing applications.

See also: carbon nanotube, graphene, fullerenes, diamondoids.