Peng Guo, Yang Qi, Chen Yue, Dong Xiang-Tao, Zhang Zaichao, Ren Xiao-Ming
State Key Laboratory of Materials-Oriented Chemical Engineering, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
Jiangsu Key Laboratory for the Chemistry of Low-Dimensional Materials, School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an 223300, China.
Dalton Trans. 2022 Aug 23;51(33):12484-12493. doi: 10.1039/d2dt01365g.
A series of tetranuclear coordination clusters LnL(HL)(μ-OH)(NO) [Ln = Dy (1·3CHCN·5HO), Gd (2·4CHCN·5HO), HL = 6,6'-dimethoxy-2,2'-[2,2-dimethylpropane-1,3-diylbis-(nitrilomethylidyne)] diphenol] and dinuclear complexes [LnZnL(NO)(HO)]·2CHCN [Ln = Dy (3), Er (4), Yb (5), Lu (6)] were prepared and characterized. Static magnetic measurements revealed the presence of ferromagnetic interactions between the Dy(III) ions and weak antiferromagnetic couplings between the Gd(III) ions in 1 and 2. Dynamic magnetic studies showed that complexes 1 and 3 exhibit slow magnetic relaxation under a zero static field as expected for single molecule magnet (SMM) behavior, whereas complex 4 is a field-induced SMM. Clear hysteresis loops were observed for 1 and 3 at 2 K, verifying their SMM behavior. Luminescence investigations demonstrated that complexes 1 and 2 show ligand-based emission and can act as luminescence thermometers below 100 K, whereas complexes 3 and 5 display the characteristic emission of lanthanide ions. From the high-resolution emission spectra of 3 and 5, the energy gaps between the ground state and excited states of Dy(III) and Yb(III) ions were determined.
制备并表征了一系列四核配位簇合物LnL(HL)(μ-OH)(NO) [Ln = Dy (1·3CHCN·5HO)、Gd (2·4CHCN·5HO)，HL = 6,6'-二甲氧基-2,2'-[2,2-二甲基丙烷-1,3-二亚基双(亚氨甲基)]二酚]和双核配合物[LnZnL(NO)(HO)]·2CHCN [Ln = Dy (3)、Er (4)、Yb (5)、Lu (6)]。静态磁性测量表明，1和2中Dy(III)离子之间存在铁磁相互作用，Gd(III)离子之间存在弱反铁磁耦合。动态磁性研究表明，配合物1和3在零静态场下表现出缓慢的磁弛豫，这是单分子磁体(SMM)行为所预期的，而配合物4是场诱导的SMM。在2 K下观察到1和3有明显的磁滞回线，证实了它们的SMM行为。发光研究表明，配合物1和2表现出基于配体的发射，并且在100 K以下可以作为发光温度计，而配合物3和5显示出镧系离子的特征发射。根据3和5的高分辨率发射光谱，确定了Dy(III)和Yb(III)离子基态和激发态之间的能隙。
