Fachbereich C-Anorganische Chemie, Bergische Universität-GH Wuppertal, Gaussstrasse 20, 42097 Wuppertal, Germany.
Inorg Chem. 2011 Mar 21;50(6):2580-9. doi: 10.1021/ic102434t. Epub 2011 Feb 22.
Oxidation of N(n-Bu(4))[B(9)H(9)] with oxygen in a mixture of dimethoxyethane and CH(2)Cl(2) leads to salts of the B(7)H(7) dianion. This is the first convenient synthesis for a seven-vertex hydro-closo-borate anion. Protonation with NEt(3)·HCl resulted in salts of the B(7)H(8) monoanion. Both closo-borate anions were isolated and characterized by (1)H, (1)H{(11)B}, (11)B, and (11)B{(1)H} NMR spectroscopy. The temperature-dependent (1)H{(11)B}, (11)B, and (11)B{(1)H} NMR spectra of B(7)H(8) were also measured. The structure of B(7)H(7) as well as of B(7)H(8) were determined by single-crystal X-ray diffraction.