Ten-vertex polyhedral monoheteroborane chemistry: syntheses, molecular structures, and nuclear magnetic resonance characterization of some 9-substituted 6-aza- and 6-thia-arachno-decaboranes

Abstract

Reactions between nido-NB₉H₁₂1 or nido-SB₉H₁₁2 and Lewis bases L under a variety of conditions gave two series of corresponding arachno compounds, exo-9-L-arachno-6-NB₉H₁₂3 and exo-9-L-arachno-6-SB₉H₁₁4 where L include NEt₃, quinoline, isoquinoline, pyridine, urotropine (uro), MeCN, MeNC, PPh₃, NH₃ and SMe₂. All these compounds were characterized by mass spectrometry together with ¹¹B and ¹H NMR spectroscopy. In some cases, the endo analogues endo-9-L-arachno-6-EB₉H₁₁, where E = NH 5 or S 6 have also been tentatively identified by NMR spectroscopy. Single-crystal X-ray diffraction studies have been carried out on an example of 3(L = MeNC) and two examples of 4(L =½ uro or MeNC).