Flash Communication: Crystalline Boron-Centered Radical Cation Stabilized by Diphosphine-Substituted closo-Hexaborate

By the reduction reaction, a boron-center radical cation (2) stabilized by a diphosphine-substituted closo-hexaborate cluster has been synthesized and fully characterized. Single-crystal X-ray diffraction, electron paramagnetic resonance (EPR) spectroscopy, and density functional theory (DFT) calculations reveal that the unpaired electron in 2 predominantly resides on the tricoordinate boron center with the high spin density of 0.767.