Preparation, characterization, and properties of 1,1′-azo-o-carbaboranes

Abstract

1-Amino-1,2-dicarbadodecaborane anions, o-RCB₁₀H₁₀CNH₂^2–(R = H, Me, or Ph), are oxidized by K[MnO₄] in liquid NH₃ to give 1,1′-azo-o-carbaboranes, RCB₁₀H₁₀CNNCB₁₀H₁₀CR (3), whereas oxidation of HCB₁₀H₁₀CCB₁₀H₁₀CNH₂^4– in the same solvent exclusively affords hydrazobis(o-carbaborane), HCB₁₀H₁₀CCB₁₀H₁₀CNHNHCB₁₀H₁₀CCB₁₀H₁₀CH. The reduction of (3) to the corresponding hydrazocarbaborane, RCB₁₀H₁₀CNHNHCB₁₀H₁₀CR (2), has been successfully achieved. closo-nido-Azocarbaboranes, RCB₁₀H₁₀CNNCB₉H₁₀CR^–(4), and nido-nido ones, RCB₉H₁₀CNNCB₉H₁₀CR^2–(5), have also been prepared by the degradation of (3) with K[OH]. Their structure and properties are discussed on the basis of spectroscopic data.