Synthesis and characterization of cyano-substituted carborane-based compounds. Molecular structure of [1-(4-C7H7)-12-(C5H3-3-(CN)-3,4-(CH3)2)-C2B10H10]

Abstract

The reaction of cyanogen chloride with [1-(4-C₇H₇)-12-(C₅H₃-3,4-(CH₃)₂)-C₂B₁₀H₁₀] (7) was found to yield two new C₅-substituted carborane cluster-based compounds, [1-(4-C₇H₇)-12-(C₅H₂-3-(CN)-3,4-(CH₃)₂)-C₂B₁₀H₁₀] (8) and [1-(4-C₇H₇)-12-(C₅H-2,4-(CN)₂-3,4-(CH₃)₂)-C₂B₁₀H₁₀] (9). This cyano-substitution pattern is in contrast to the known substitution for the analogous organic quinarene[5.6.7] system. The observed unique cluster-based products may be understood by a combination of steric and electronic effects. Compounds 8 and 9 were characterized by complete multinuclear NMR, ¹H-¹H COSY NMR, ¹H-¹³C HMQC NMR, FTIR, UV-Vis, IR, MS data and a single crystal analysis for 8 [X-ray data for 8: C₁₇H₂₅B₁₀N, monoclinic, space groupP2₁/n with cell constants a = 8.6794(17) Å, b = 11.021(2) Å, c = 43.175(9) Å, β = 91.00(3)°, V = 4129.2(14) ų, Z = 8, R₁ = 0.0729, wR₂ = 0.1464].