Novel non-spherical deltahedra in tritungstaboranes related to the experimentally known (Cp3W3)-W-star(H)B8H8

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

来源：New Journal of Chemistry, 2017, 41(19): 10640-10651.

DOI：10.1039/c7nj01801k

The geometries and energetics of tritungstaboranes Cp3W3(H)Bn-3Hn-3 (Cp = eta(5)-C5H5; n = 5 to 12), related to the experimentally known (Cp3W3)-W-star(H)B8H8 (Cp-star = eta(5)-Me5C5), have been investigated using density functional theory and coupled cluster calculations. Such low-energy structures have central W3Bn-3 deltahedra with superimposed bonded W-3 triangles. The "extra'' hydrogen atom either bridges a deltahedral edge or caps a deltahedral face containing at least one tungsten atom. The tungsten atoms are located at degree 5 to 7 vertices in regions of a relatively low surface curvature whereas the boron atoms are located at degree 3 to 5 vertices in regions of a relatively high surface curvature. The five lowest-energy structures of the 11-vertex tritungstaborane Cp3W3(H)B8H8 all have the same central W3B8 deltahedron and differ only by the location of the "extra'' hydrogen atom. The isosceles W-3 triangles in these structures have two long similar to 3.0 angstrom W-W edges through the inside of the deltahedron with the third shorter W-W edge of similar to 2.7 to similar to 2.8 angstrom corresponding to a surface deltahedral edge. The five Cp3W3(H)B8H8 structures differ only by the location of the "extra'' hydrogen atom. The lowest energy such structure has the "extra'' hydrogen atom bridging the surface W-W bond and corresponds to the experimental (Cp3W3)-W-star(H)B8H8 structure, as determined using X-ray crystallography.

• 出版日期2017-10-7