Bottleable Neutral Analogues of [B2H5]− as Versatile and Strongly Binding η2 Donor Ligands. Issue 21 (25th April 2018) - Wang, Sunewang R.
Abstract: Herein we report the discovery that two bottleable, neutral, base‐stabilized diborane(5) compounds are able to bind strongly to a number of copper(I) complexes exclusively through their B−B bond. The resulting complexes represent the first known complexes containing unsupported, neutral σB−B diborane ligands. Single‐crystal X‐ray analyses of these complexes show that the X−Cu moiety (X=Cl, OTf, C6 F5 ) lies opposite the bridging hydrogen atom of the diborane and is near perpendicular to the B−B bond, interacting almost equally with both boron atoms and causing a B−B bond elongation. DFT studies show that σ donation from and π backdonation to the pseudo‐π‐like B−B bond account for their formation. Astoundingly, these copper σB−B complexes are inert to ligand exchange with pyridine under either heating or photoirradiation. Abstract : B together : Two bottleable, neutral, base‐stabilized diborane(5) compounds are able to bind strongly to a number of copper(I) complexes exclusively through their B−B bond. The resulting complexes represent the first complexes containing unsupported, neutral σB−B diborane ligands. SIMes=1, 3‐bis(2, 4, 6‐trimethylphenyl)‐4, 5‐dihydroimidazolidin‐2‐ylidene.