title: Stability of N18C6H6: triangular versus hexagonal structure.
abstract: Large nitrogen cage molecules Nx have been previously shown to prefer elongated, cylindrical structures with triangular caps versus more spherical structures composed entirely of pentagons and hexagons. It was argued that this preference derived from the electronic properties of the nitrogen atoms, including the lone pairs. In the current study, the same structural comparison is carried out, with the substitution of C-H-bonding groups for six of the nitrogens. Various substitution patterns on the cylindrical (triangular) and spherical (hexagonal) frameworks are examined. Isomers of N18C6H6 are studied by theoretical calculations to determine the relative stability of triangular versus hexagonal structures, as well as the stability effects of the substitution patterns on each framework. Hartree-Fock theory, density functional theory (PBE1PBE), and perturbation theory (MP2) are employed, in conjunction with the correlation-consistent basis sets of Dunning. Stability trends within each class of molecules and between the two classes of molecules are calculated and discussed.
authors.affiliation: Department of Physical Sciences, Alabama State University, Montgomery, Alabama 36101, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Pinkston
authors.forename: Deana
authors.initials: D
authors.lastname: McAdory
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Jones
authors.forename: Danielle
authors.initials: D
authors.lastname: Shields
authors.forename: Ramola
authors.initials: R
authors.lastname: Langham
authors.forename: Kasha
authors.initials: K
authors.lastname: Casey
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Strout
mesh_terms: D001554:Benzene / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry*; D007536:Isomerism; D008958:Models, Molecular; D008968:Molecular Conformation
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; D002244:Carbon; D001554:Benzene