镧系碳硼烷配合物中阳离子依赖性反向氢键和磁交换耦合的研究。

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

作者信息

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

机构信息

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.

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.

出版信息

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

Ten lanthanacarborane complexes were synthesized to study the rare B-H∙∙∙M inverse hydrogen bonds (IHBs). The average bonding energy of B-H∙∙∙Ln 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∙∙∙Ln IHBs in detail, and the coupling constant is determined to be -2.0 cm, 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∙∙∙M IHBs are cation-dependent. If M = Na, the B-H∙∙∙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.

合成了十种镧系碳硼烷配合物以研究罕见的B-H∙∙∙M反向氢键（IHB）。理论上确定B-H∙∙∙Ln的平均键能大于24 kJ/mol，这与中等强度的氢键（21 - 56 kJ/mol）相当。除了核磁共振和红外光谱外，还使用磁力计详细研究了通过此类B-H∙∙∙Ln IHB的交换耦合相互作用，耦合常数确定为-2.0 cm，其强度足以与单原子桥联的镝（III）配合物相媲美。两种含有咪唑啉亚氨基的配合物表现出大于1000 K的磁化反转能垒，且交换偏置效应明显。此外，B-H∙∙∙M IHB的键强取决于阳离子。如果M = Na，B-H∙∙∙Na的键能降至14 kJ/mol，二聚过程不再可逆。交换偏置效应也消失了。我们相信这一发现扩展了我们对IHB的认识。