Polyhedral thiaborane chemistry: a comparative nuclear magnetic resonance study of arachno-[6-SB9H12]– and nido-6-SB9H11

Abstract

A nuclear magnetic resonance study of nido-6-SB₉H₁₁ and arachno-[6-SB₉H₁₂]^– using ¹¹B, ¹¹B-{¹H}, ¹H-{¹¹B}, [¹¹B–¹¹B]-COSY, and [¹H–¹H]-COSY techniques has enabled unequivocal assignment of the ¹¹B and ¹H spectra, and has thereby shown that the basic known behavioural patterns of their binary borane analogues (arachno-[B₁₀H₁₄]^2– and nido-B₁₀H₁₄) also hold for the 6-thiadecaborane system. Interestingly, the effects on cluster nuclear shielding upon replacement of the decarborane B(6) centres with sulphur are very similar for both systems in spite of the fundamentally different arachno versus nido electronic structures. A long-term hydrolysis product of [6-SB₉H₁₂]^– is confirmed as [endo-9-(OH)-arachno-6-SB₉H₁₁]^–.