A study of cation-dependent inverse hydrogen bonds and magnetic exchange-couplings in lanthanacarborane complexes

Peng-Bo Jin; Qian-Cheng Luo; Yuan-Qi Zhai; Yi-Dian Wang; Yan Ma; Lei Tian; Xinliang Zhang; Chao Ke; Xu-Feng Zhang; Yi Lv; Yan-Zhen Zheng

doi:10.1016/j.isci.2021.102760

A study of cation-dependent inverse hydrogen bonds and magnetic exchange-couplings in lanthanacarborane complexes

iScience. 2021 Jun 19;24(7):102760. doi: 10.1016/j.isci.2021.102760. eCollection 2021 Jul 23.

Authors

Peng-Bo Jin¹, Qian-Cheng Luo¹, Yuan-Qi Zhai¹, Yi-Dian Wang¹, Yan Ma¹, Lei Tian², Xinliang Zhang³, Chao Ke⁴, Xu-Feng Zhang⁵, Yi Lv⁵, Yan-Zhen Zheng¹

Affiliations

¹ Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University Shenzhen Research School, State Key Laboratory for Mechanical Behavior of Materials, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter and School of Chemistry, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi, P.R. China.
² State Key Laboratory of Military Stomatology, National Clinical Research Center of Oral Diseases, Shaanxi Key Laboratory of Oral Diseases, Department of Cranio-facial Trauma and Orthognathic Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an, No. 145, Changle Xi Road, 710032 Xi'an, Shaanxi, P.R. China.
³ Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, 710054 Xi'an, Shaanxi, P.R. China.
⁴ Department of Orthopaedic Trauma, Honghui Hospital, College of Medicine, Xi'an Jiaotong University, 710054 Xi'an, Shaanxi, P.R. China.
⁵ Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, 710061 Xi'an, Shaanxi, P.R. China.

Abstract

Ten lanthanacarborane complexes were synthesized to study the rare B-H^δ-∙∙∙Mⁿ⁺ inverse hydrogen bonds (IHBs). The average bonding energy of B-H^δ-∙∙∙Ln³⁺ is theoretically determined to be larger than 24 kJ/mol, which is comparable to moderately strong hydrogen bonds (21-56 kJ/mol). In addition to NMR and IR, magnetometer was used to study the exchange-coupling interaction via such B-H^δ-∙∙∙Ln³⁺ IHBs in detail, and the coupling constant is determined to be -2.0 cm^-1, which is strong enough to compare with single-atom bridged dysprosium(III) complexes. Two imidazolin-iminato incorporated complexes have shown energy barrier for magnetization reversal larger than 1000 K, and the exchange-biasing effects are evident. Moreover, the bonding strengths of B-H^δ-∙∙∙Mⁿ⁺ IHBs are cation-dependent. If M = Na, the B-H^δ-∙∙∙Na⁺ bonding energy is reduced to 14 kJ/mol, and the dimerization process is no longer reversible. The exchange-biasing effect is also disappeared. We believe such a finding extends our knowledge of IHBs.

Keywords: chemistry; inorganic chemistry; magnetism; molecular inorganic chemistry.