2-Substituted icosahedral monocarbon carboranes. Part 1. Synthesis via boron insertion

Abstract

New 2-substituted icosahedral monocarbon carboranes have been synthesised by functionalised boron insertion. The compounds [NBu^n₄][2-Ph-closo-1-CB₁₁H₁₁]1, [PPh₄][2-(p-MeC₆H₄)-closo-1-CB₁₁H₁₁]2, [N(CH₂Ph)Me₃][2-F-closo-1-CB₁₁H₁₁]3, 2-Me₃N-closo-1-CB₁₁H₁₁4 and [PPh₄][2-Cl(CH₂)₄O-closo-1-CB₁₁H₁₁]5 were characterised by ¹H, ¹¹B and ¹¹B–¹¹B correlation NMR spectroscopy. The crystal structure of 5 shows a cage distortion that is postulated to result from π interaction of the substituent with the cluster. Crystal data: triclinic, space group P, a= 10.672(2), b= 11.047(2), c= 14.203(3)Å, α= 75.97(2), β= 87.84(2), γ= 83.22(2)°, Z= 2. Final R= 0.042 for 3951 reflections with I > 2σ(I).