Synthesis and structure of the coordinatively unsaturated boron subphthalocyanine cation, [B(SubPc)]+

The boron subphthalocyanine cation, B(SubPc)+, has been prepared as a salt of a weakly coordinating carborane anion, CHB11Me5Br6−, by a metathesis reaction of Et3Si(CHB11Me5Br6) with B(SubPc)Cl. The separation of the cation and anion in the X‐ray structure indicates coordinative unsaturation at the boron center, and this is corroborated by DFT calculations. A strongly Lewis acidic nature for the B(SubPc)+ cation is indicated by its hydrolysis to an unusual product, the di‐meso‐N‐protonated μ‐oxo dimer, [H(SubPc)B‐O‐B(SubPc)H]2+.