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

• DOI: 10.1016/j.isci.2021.102760
• Publication Date: 2021-06-19T15:07:12Z
• Authors: 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
• Keywords: magnetism; Science; Q; inorganic chemistry; molecular inorganic chemistry; chemistry; 01 natural sciences; Article; 0104 chemical sciences

Ten lanthanacarborane complexes were synthesized to study the rare B-Hδ-∙∙∙Mn+ inverse hydrogen bonds (IHBs). The average bonding energy of B-Hδ-∙∙∙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-Hδ-∙∙∙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-Hδ-∙∙∙Mn+ IHBs are cation-dependent. If M = Na, the B-Hδ-∙∙∙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.