Syntheses and Dft/Giao/Nmr Study of Polyhedral Selenaboranes: the First Selenahexaborane(5) Closo-1-Seb5cl5

The six-vertex closo-1-SeB5Cl5 (1) and the 12-vertex closo-1-SeB11Cl11 (2) selenaboranes were prepared in low yields from the co-pyrolysis reaction of B2Cl4 with Se2Cl2 at 330 °C. Both compounds are sublimable, colorless solids and were tentatively characterized by 11B NMR and high-resolution mass spectroscopy. DFT/GIAO/NMR calculations support octahedral and icosahedral arrangements for 1 and 2, respectively, as expected due to their closo electron counts. Compound 1 represents the first example of a polyhedral selenaborane with a cluster size smaller than 10 vertices.