Synthesis and Structural Characterization of Ammonio/Hydroxo Undecachloro‐ closo ‐Dodecaborates [B 12 Cl 11 NH 3 ] – /[B 12 Cl 11 OH] 2– and Their Derivatives

Anions [B 12 Cl 11 NH 3 ] – and [B 12 Cl 11 OH] 2– were prepared in high yields from the known precursors [B 12 H 11 NH 3 ] – and [B 12 H 11 OH] 2– by using SO 2 Cl 2 . Reaction monitoring by 11 B NMR spectroscopy and ESI‐mass spectrometry indicated that SO 2 Cl 2 serves as a convenient chlorination reagent in both transformations. This chemical is an alternative to SbCl 5 or chlorine gas, which have been used in reported procedures. [B 12 Cl 11 NMe 3 ] – was prepared in 92 % overall yield from [B 12 H 11 NH 3 ] – salts without isolation of the unmethylated intermediate. Starting from [B 12 Cl 11 OH] 2– , [B 12 Cl 11 OS(O)CF 3 ] 2– was obtained unexpectedly by using Tf 2 O in pyridine/CH 2 Cl 2 by a rare reduction process, while [B 12 Cl 11 OTs] 2– was synthesized by using TsCl in pyridine. All compounds were fully characterized by NMR and IR spectroscopy and ESI‐mass spectrometry. [Ag(MeCN) 4 ][B 12 Cl 11 NH 3 ], [Et 4 N][B 12 Cl 11 NH 3 ], [Me 4 N] 2 [B 12 Cl 11 OH], [Et 3 NH][Cs][B 12 Cl 11 OH], [Ph 3 PMe] 2 [B 12 Cl 11 OS(O)CF 3 ], and [MePPh 3 ] 2 [B 12 Cl 11 OTs] were studied by X‐ray diffraction.