title: Is the isolated pentagon rule always satisfied for metallic carbide endohedral fullerenes?
abstract: Quantum-chemical calculations reveal that metallic carbide endohedral fullerene Y(2)C(2)@C(84) possesses a novel fullerene cage, C(1)(51383)-C(84), with one pair of pentagon adjacencies. One of the encapsulated yttrium atoms is located on the adjacent pentagons, while the other stays on a hexagonal ring in the fullerene cage. As one of numerous metallic carbide endohedral fullerenes, Y(2)C(2)@C(1)(51383)-C(84) is the first example that violates the well-known isolated pentagon rule (IPR). More interestingly, compared with the fact that Sc(2)C(2)@C(84) has a conventional IPR-satisfying cage, D(2d)(51591)-C(84), Y(2)C(2)@C(84) utilizes the novel fullerene cage C(1)(51383)-C(84) with one pair of pentagon adjacencies.
authors.affiliation: Institute for Chemical Physics and Department of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhao
authors.forename: Sheng-Tao
authors.initials: ST
authors.lastname: Li
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase