Zhong Xiang, Li Dong-Yang, Cao Chen, Luo Tong-Kai, Hu Zhao-Bo, Peng Yan, Liu Sui-Jun, Zheng Yan-Zhen, Wen He-Rui
School of Chemistry and Chemical Engineering, Jiangxi Provincial Key Laboratory of Functional Crystalline Materials Chemistry, Jiangxi University of Science and Technology, Ganzhou, Jiangxi Province 341000, P. R. China.
Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shanxi Province 710054, P. R. China.
Inorg Chem. 2024 Nov 18;63(46):21909-21918. doi: 10.1021/acs.inorgchem.4c03012. Epub 2024 Oct 31.
Three mononuclear Dy compounds [DyL(PhSiO)][BPh]·MeCN·2HO (), [DyL(PhSiO)][BPh]·CHOH·HO (), and [DyL(PhSiO)(OAc)][BPh]·CHOH·3HO () and their corresponding Y diluted analogues [DyYL(PhSiO)][BPh]·MeCN·2HO (), [DyYL(PhSiO)][BPh]·CHOH·HO (), and [DyYL(PhSiO)(OAc)][BPh]·CHOH·3HO () were synthesized with hexaazamacrocyclic Schiff base ligands as an equatorial ligand. The substituents in the equatorial hexaazamacrocyclic Schiff base ligand show a significant effect on the replacement of the axial ligands. Compounds , , and are typical zero dc field single-molecule magnets with effective energy barriers () of 1092(6), 946.1(7), and 150.1(9) K, respectively. Although the effective energy barriers of and are close, the magnetic hysteresis remains open up to 20 K for , twice as large as that of (10 K), which is different from the previously reported compounds, probably due to nonplanarity N6 in the equator. calculations indicate that the ground states of compounds and exhibit high anisotropy and pure second and third excited states, while compound exhibits pure ground-state anisotropy and highly mixed excited states, leading to the easy occurrence of quantum tunneling of magnetization between the ground and excited states in compound . This work indicates that the substituents in equatorial hexaazamacrocyclic Schiff base ligands have a significant effect on the construction and magnetic properties of Dy SIMs with D symmetry.
三种单核镝化合物[DyL(PhSiO)][BPh]·MeCN·2HO（）、[DyL(PhSiO)][BPh]·CHOH·HO（）和[DyL(PhSiO)(OAc)][BPh]·CHOH·3HO（）以及它们相应的镱稀释类似物[DyYL(PhSiO)][BPh]·MeCN·2HO（）、[DyYL(PhSiO)][BPh]·CHOH·HO（）和[DyYL(PhSiO)(OAc)][BPh]·CHOH·3HO（）以六氮杂大环席夫碱配体作为赤道配体合成。赤道六氮杂大环席夫碱配体中的取代基对轴向配体的取代有显著影响。化合物、和是典型的零直流场单分子磁体，有效能垒（）分别为1092(6)、946.1(7)和150.1(9)K。尽管和的有效能垒相近，但对于，磁滞在高达20K时仍保持打开，是（10K）的两倍，这与先前报道的化合物不同，可能是由于赤道处的N6非平面性。计算表明，化合物和的基态表现出高各向异性以及纯的第二和第三激发态，而化合物表现出纯的基态各向异性和高度混合的激发态，导致化合物中基态和激发态之间容易发生磁化量子隧穿。这项工作表明，赤道六氮杂大环席夫碱配体中的取代基对具有D对称性的镝单分子磁体的结构和磁性能有显著影响。
