Terminal-fluoride-coordinated air-stable chiral dysprosium single-molecule magnets

Abstract

Terminal fluoride ligands generate strongly magnetic anisotropy in air-stable chiral dysprosium enantiomers supported by bulky equatorial macrocycle, exhibting typical zero-field single-molecule magnets behaviour.

Assembly of pinwheel/twist-shaped chiral lanthanide clusters with rotor structures by an annular/linear growth mechanism and their magnetic properties

“…52 In 2022, Tang et al reported two mutually enantiomeric chiral mononuclear dysprosium complexes constructed from bulky equatorial macrocyclic ligands and exhibited typical zero-field SMM behavior. 53 Based on the above studies, chiral lanthanide SMMs are distributed in low-nuclearity lanthanide complexes, especially mononuclear ones. [48][49][50][51][52][53] In the high-nuclearity lanthanide cluster structure, the metal centers are densely arranged, resulting in the mutual cancellation of their magnetic axes and disorders.…”

“…53 Based on the above studies, chiral lanthanide SMMs are distributed in low-nuclearity lanthanide complexes, especially mononuclear ones. [48][49][50][51][52][53] In the high-nuclearity lanthanide cluster structure, the metal centers are densely arranged, resulting in the mutual cancellation of their magnetic axes and disorders. 8,9 SMMs based on high-nuclear lanthanide clusters are rarely reported.…”

Air-stable chiral double-decker Dy(iii) macrocycles with fluoride ion as the sole axial ligand

“…19 In general, polydentate ligands are essential to prepare an air-stable SMM with fluoride ligands as they not only stabilize the molecular skeleton but also leave a suitable space for the coordination of fluoride ions to the metal center, such as 1,4,7,10-tetrakis(2-pyridylmethyl)-1,4,7,10-tetraaza-cyclododecane, 20 tris(3-(2-pyridyl)pyrazolyl)hydroborate, 21 Schiff-base hexaazamacrocycles etc. 22 Indeed, we have reported two chiral macrocyclic mononuclear Dy(III) compounds featuring terminal fluoride coordination. 22 However, the coordination of H 2 O causes a deviation of the local symmetry from the hexagonal bipyramidal geometry.…”

“…22 Indeed, we have reported two chiral macrocyclic mononuclear Dy(III) compounds featuring terminal fluoride coordination. 22 However, the coordination of H 2 O causes a deviation of the local symmetry from the hexagonal bipyramidal geometry. Herein, we used a less sterically hin-dered Schiff-base macrocycle and fluoride ion as the equatorial and axial ligand, respectively, and obtained two air-stable fluoride-bridged double-decker Dy(III) macrocyclic enantiomers All reactions were performed under aerobic conditions.…”

“…22 Indeed, we have reported two chiral macrocyclic mononuclear Dy( iii ) compounds featuring terminal fluoride coordination. 22 However, the coordination of H 2 O causes a deviation of the local symmetry from the hexagonal bipyramidal geometry. Herein, we used a less sterically hindered Schiff-base macrocycle and fluoride ion as the equatorial and axial ligand, respectively, and obtained two air-stable fluoride-bridged double-decker Dy( iii ) macrocyclic enantiomers (Scheme 1), [Dy 2 (L E ) 2 (μ 2 -F) 2 F 2 ][BPh 4 ] 2 ·4CH 2 Cl 2 ·2H 2 O (L E = SSSSS -/ RRRR -(2 E ,6 E ,9 E ,13 E )-4,5,11,12-tetraphenyl-3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane-2,6,9,13-tetraene for 1/2 ), showing strong intramolecular ferromagnetic coupling and two-step relaxation of magnetization under a zero dc field.…”