A seven-coordinated DyIIIsingle-ion magnet withC2vsymmetry constructed by a multidentate Schiff-base ligand

Two isostructural mononuclear lanthanide complexes [Ln(HL)Cl](Ln = Dy(1), Tb(2), HL = 6,6′-(((oxybis(2,1-phenylene))bis-(azanylylidene))bis(methanylylidene))bis(2-methoxyphenol)) were synthesized by solvothermal reaction. In both complexes, the Lnions are seven-coordinated with a LnOClcoordination core in theCsymmetry. Magnetic measurements reveal that Dycomplex1shows field-induced two-step magnetization relaxation processes withU= 53.47 K (slow relaxation) and 26.94 K (fast relaxation), respectively. The analysis of energy levels and eigenstates suggests that the mixed ground state doublets result in the field induced single-ion magnet behaviour of complex1. In addition, the magneto-structural correlation, including the easy magnetic axis of Dyion, was further discussed based on an electrostatic model calculation. This work gave another example of designing low-coordinated Ln-SIMs by utilizing a multidentate Schiff-base ligand with large steric hindrance.