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).