Nonspherical Deltahedra in Low-Energy Dicarbalane Structures Testing the Wade-Mingos Rules: The Regular Icosahedron Is Not Favored for the 12-Vertex Dicarbalane

作者：Attia Amr A A; Lupan Alexandru^*; King R Bruce

来源：Inorganic Chemistry, 2015, 54(23): 11377-11384.

DOI：10.1021/acs.inorgchem.5b02014

Theoretical studies on the dicarbalanes C2Aln-2Men (n = 7-14; Me = methyl) predict both carbon atoms to be located at degree 4 vertices of a central C2Aln-2 deltahedron in the lowest energy structures. As a consequence, deltahedra having two degree 4 vertices, two degree 6 vertices, and eight degree S vertices rather than the regular icosahedron having exclusively degree 5 vertices are found for the 12-vertex dicarbalane C2Al10Me12. However, the lowest energy C2Aln-2Men (n = 7-11) structures are based on the same most spherical (closo) deltahedra as the corresponding deltahedral boranes. The lowest energy structures for the 13- and 14-vertex systems C2Aln-2Men (n = 13 and 14) are also deltahedra having exactly two degree 4 vertices for the carbon atoms. The six-vertex C2Al4Me6 system is exceptional since bicapped tetrahedral and capped square pyramidal structures with degree 3 vertices for the carbon atoms are energetically preferred over the octahedral structure suggested by the Wade-Mingos rules.

• 出版日期2015-12-7