title: Lowering the reduction potential of a boron compound by means of the substituent effect of the boryl group: one-electron reduction of an unsymmetrical diborane(4).
abstract: We have clarified and observed the high electron affinity of pinB-BMes2 (1; Mes = mesityl, pin = pinacolato). By using electrochemistry, it was shown that 1 has a higher electron affinity than those of B2pin2 and Mes3B. One-electron reduction of 1 gave the corresponding radical anion. The ESR spectroscopy and DFT calculation revealed the unsymmetrical distribution of electron density over the B-B bond. UV/Vis spectroscopy showed that the SOMO-related absorption supports the deep purple color of the radical anion. DFT studies on the torsion angle dependency of the LUMO levels and relative energies revealed the reason why 1 has high electron affinity as a result of the substituent effect of the Bpin group.
authors: Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, 112-8551 Tokyo (Japan) http://www.chem.chuo-u.ac.jp/∼element/index-e.html.
authors: Hiroki
authors: H
authors: Asakawa
authors: Ka-Ho
authors: KH
authors: Lee
authors: Ko
authors: K
authors: Furukawa
authors: Zhenyang
authors: Z
authors: Lin
authors: Makoto
authors: M
authors: Yamashita
keywords: boranes; density functional calculations; radical anions; substituent effect; torsion angles