Quadruple bonding between iron and boron in the BFe(CO)3- complex

Chaoxian Chi; Jia-Qi Wang; Han-Shi Hu; Yang-Yang Zhang; Wan-Lu Li; Luyan Meng; Mingbiao Luo; Mingfei Zhou; Jun Li

doi:10.1038/s41467-019-12767-5

Quadruple bonding between iron and boron in the BFe(CO)₃^- complex

Nat Commun. 2019 Oct 17;10(1):4713. doi: 10.1038/s41467-019-12767-5.

Authors

Chaoxian Chi¹, Jia-Qi Wang², Han-Shi Hu³, Yang-Yang Zhang², Wan-Lu Li², Luyan Meng¹, Mingbiao Luo¹, Mingfei Zhou⁴, Jun Li^{5

6}

Affiliations

¹ School of Chemistry, Biological and Materials Sciences, East China University of Technology, 330013, Nanchang, Jiangxi Province, China.
² Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, 100084, Beijing, China.
³ Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, 100084, Beijing, China. hshu@mail.tsinghua.edu.cn.
⁴ Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 200433, Shanghai, China. mfzhou@fudan.edu.cn.
⁵ Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, 100084, Beijing, China. junli@tsinghua.edu.cn.
⁶ Department of Chemistry, Southern University of Science and Technology, 518055, Shenzhen, China. junli@tsinghua.edu.cn.

Abstract

While main group elements have four valence orbitals accessible for bonding, quadruple bonding to main group elements is extremely rare. Here we report that main group element boron is able to form quadruple bonding interactions with iron in the BFe(CO)₃^- anion complex, which has been revealed by quantum chemical investigation and identified by mass-selected infrared photodissociation spectroscopy in the gas phase. The complex is characterized to have a B-Fe(CO)₃^- structure of C_3v symmetry and features a B-Fe bond distance that is much shorter than that expected for a triple bond. Various chemical bonding analyses indicate that the complex involves unprecedented B≣Fe quadruple bonding interactions. Besides the common one electron-sharing σ bond and two Fe→B dative π bonds, there is an additional weak B→Fe dative σ bonding interaction. This finding of the new quadruple bonding indicates that there might exist a wide range of boron-metal complexes that contain such high multiplicity of chemical bonds.

Publication types

Research Support, Non-U.S. Gov't