Double C-H bond activation of acetylene by atomic boron in forming aromatic cyclic-HBC2BH in solid neon

Jiwen Jian; Wei Li; Xuan Wu; Mingfei Zhou

doi:10.1039/c7sc01399j

Double C-H bond activation of acetylene by atomic boron in forming aromatic cyclic-HBC₂BH in solid neon

Chem Sci. 2017 Jun 1;8(6):4443-4449. doi: 10.1039/c7sc01399j. Epub 2017 Apr 19.

Authors

Jiwen Jian¹, Wei Li¹, Xuan Wu¹, Mingfei Zhou¹

Affiliation

¹ Department of Chemistry , Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials , Collaborative Innovation Center of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , China . Email: mfzhou@fudan.edu.cn.

Abstract

The organo-boron species formed from the reactions of boron atoms with acetylene in solid neon are investigated using matrix isolation infrared spectroscopy with isotopic substitutions as well as quantum chemical calculations. Besides the previously reported single C-H bond activation species, a cyclic-HBC₂BH diboron species is formed via double C-H bond activation of acetylene. It is characterized to have a closed-shell singlet ground state with planar D_2h symmetry. Bonding analysis indicates that it is a doubly aromatic species involving two delocalized σ electrons and two delocalized π electrons. This finding reveals the very first example of double C-H bond activation of acetylene in forming new organo-boron compounds.