Graphyne

Graphyne is a theorized allotrope of carbon. Its structure is one-atom-thick planar sheets of sp and sp-bonded carbon atoms arranged in crystal lattice. It can be seen as a lattice of benzene rings connected by acetylene bonds. Depending on the content of acetylene groups, graphyne can be considered a mixed hybridization, sp, where 1 < n < 2, and thus differs from the hybridization of graphene (considered pure sp) and diamond (pure sp).