Liu Cai-Ming, Sun Rong, Wang Bing-Wu, Hao Xiang, Li Xi-Li
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing100190, China.
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China.
Inorg Chem. 2022 Nov 21;61(46):18510-18523. doi: 10.1021/acs.inorgchem.2c02743. Epub 2022 Nov 8.
By changing the counterions (ClO and CFSO) and the coordination anions (Cl and Br), we investigated their influences on the structures and performances of a class of ZnDy chiral single-molecule magnets (SMMs), which are based on a pair of chiral Schiff bases ,-HL and ,-HL {,-HL = 2-(()-((1,2)-2-(()-2-hydroxy-3-methoxybenzylideneamino)cyclohexylimino)methyl)-6-methoxyphenol and ,-HL = 2-(()-((1,2)-2-(()-2-hydroxy-3-methoxybenzylideneamino)cyclohexylimino)methyl)-6-methoxyphenol}. Three pairs of chiral ZnDy Schiff base complexes were obtained by directed synthesis, which are DyZn(,-)Cl(HO)·0.5MeOH·0.25HO (-) and [DyZn(,-)Cl(HO)]DyZn(,-)Cl(MeOH)·MeOH·0.5HO (-), DyZn(,-)Cl(HO)·0.5MeOH (-) and [DyZn(,-)Cl(HO)]DyZn(,-)Cl(MeOH)·MeOH (-), and DyZn(,-)Br(HO)·0.25MeOH (-) and [DyZn(,-)Br(HO)]DyZn(,-)Br(MeOH) (-). They all exhibit good SMM behaviors, and their magnet relaxation is regulated by not only the counterions (ClO and CFSO) but also the coordination anions (Cl and Br); these anions also have important effects on the second-harmonic generation (SHG) and third harmonic generation (THG) nonlinear optical properties. Interestingly, in the -configuration complexes, the coordination solvent molecule of the Dy ion on half of the molecules is the methanol molecule instead of the water molecule. This change in the coordinating solvent molecule can also significantly affect the SMM behaviors and the SHG and THG nonlinear optical properties. Moreover, ab initio calculations were applied to rationally explain the SMM properties.
通过改变抗衡离子（ClO⁻和CF₃SO₃⁻）以及配位阴离子（Cl⁻和Br⁻），我们研究了它们对一类基于一对手性席夫碱、-HL和、-HL {、-HL = 2-((()-((1,2)-2-((()-2-羟基-3-甲氧基亚苄基氨基)环己基亚氨基)甲基)-6-甲氧基苯酚，且、-HL = 2-((()-((1,2)-2-((()-2-羟基-3-甲氧基亚苄基氨基)环己基亚氨基)甲基)-6-甲氧基苯酚)}的ZnDy手性单分子磁体（SMMs）的结构和性能的影响。通过定向合成得到了三对手性ZnDy席夫碱配合物，分别是DyZn(、-)Cl(H₂O)·0.5MeOH·0.25H₂O (-)和[DyZn(、-)Cl(H₂O)]DyZn(、-)Cl(MeOH)·MeOH·0.5H₂O (-)，DyZn(、-)Cl(H₂O)·0.5MeOH (-)和[DyZn(、-)Cl(H₂O)]DyZn(、-)Cl(MeOH)·MeOH (-)，以及DyZn(、-)Br(H₂O)·0.25MeOH (-)和[DyZn(、-)Br(H₂O)]DyZn(、-)Br(MeOH) (-)。它们均表现出良好的SMM行为，并且它们的磁弛豫不仅受抗衡离子（ClO₄⁻和CF₃SO₃⁻）调控，还受配位阴离子（Cl⁻和Br⁻）调控；这些阴离子对二次谐波产生（SHG）和三次谐波产生（THG）非线性光学性质也有重要影响。有趣的是，在-构型配合物中，一半分子上Dy离子的配位溶剂分子是甲醇分子而非水分子。配位溶剂分子的这种变化也能显著影响SMM行为以及SHG和THG非线性光学性质。此外，还应用了从头算计算来合理解释SMM性质。
