Bromination Mechanism of closo-1,2-C2B10H12 and the Structure of the Resulting 9-Br-closo-1,2-C2B10H11 Determined by Gas Electron Diffraction

0532249 - ÚACH 2021 RIV DE eng J - Journal Article
Holub, Josef - Vishnevskiy, Y. V. - Fanfrlík, Jindřich - Mitzel, N. W. - Tikhonov, D. - Schwabedissen, J. - McKee, M.L. - Hnyk, Drahomír
Bromination Mechanism of closo-1,2-C2B10H12 and the Structure of the Resulting 9-Br-closo-1,2-C2B10H11 Determined by Gas Electron Diffraction.
ChemPlusChem. Roč. 85, č. 12 (2020), s. 2606-2610. ISSN 2192-6506. E-ISSN 2192-6506
R&D Projects: GA ČR(CZ) GA19-17156S
Institutional support: RVO:61388980 ; RVO:61388963
Keywords : bromination * carboranes * electron diffraction * reaction pathways * transition states
OECD category: Inorganic and nuclear chemistry; Physical chemistry (UOCHB-X)
Impact factor: 2.863, year: 2020
Method of publishing: Open access

9‐Br‐ closo ‐1,2‐C 2 B 10 H 11 has been prepared and its gas‐phase structure has been examined by means of gas electron diffraction. The structure of the carbaborane core is similar to the structure of the parent compound, which is of C 2v symmetry. A DFT‐based search for the corresponding reaction pathway of the bromination of closo ‐1,2‐C 2 B 10 H 12 has revealed that the catalytic amount of aluminum reduces the barrier of the initial attack of the bromination agent toward the negatively charged part of the icosahedral carbaborane, i.e. the first transition state, from about 40 to about 27 kcal/mol. The Br‐Br bond is weakened by an intermediate binding to the large π‐hole on the aluminum atom of AlBr 3 , which is the driving force for the AlBr 3 ‐catalyzed bromination.

Permanent Link: http://hdl.handle.net/11104/0313545