Four New Families of Polynuclear Zn-Ln Coordination Clusters. Synthetic, Topological, Magnetic, and Luminescent Aspects

Abstract

12) with robust and novel topologies. Synthetic aspects are discussed. A comprehensive topological analysis of all reported Zn II /Ln III CCs with a core nuclearity of four and above is presented and identifies that families (4-6) and (7-9) are the first examples of the 2,3,4M6-1 motif in Zn II /Ln III chemistry. Magnetic studies are presented for the Dy III analogues (1, 7 and 10) are presented, 7 demonstrates field-induced slow relaxation of the magnetization. Fluorescence studies are also discussed.

The first exploration of coordination chemistry using a methyl substituted o-vanillin based ligand: an example starting with Dy4/Zn2Dy2 systems displaying slow relaxation of magnetization

“…Nevertheless, the energy barriers are similar to that obtained for some structurally analogous reported Dy 4 and Zn 2 Dy 2 complexes. [44][45][46][47][48] The resultant low energy barriers are consistent with no peak in the out-of-phase ac susceptibility down to 2 K. Literature reports reveal that several factors such as geometry, magnetic anisotropy, metal-metal interaction, crystal field effect, etc. play an important role in the slow relaxation of magnetisation.…”

Influence of the Different Types of Auxiliary Noncarboxylate Organic Ligands on the Topologies and Magnetic Relaxation Behavior of Zn–Dy Heterometallic Single Molecule Magnets

“…The first reason is that the saturated d 10 electronic configuration can prevent the quenching of Dy III luminescence, which favors the Zn−Dy complexes exhibiting luminescence and SMM multifunctional properties. 13,27,29 The second reason is that magnetic coupling between Zn II and Dy III ions can be eliminated. This leads to the SMM performance of Zn−Dy complexes superior to the complexes containing paramagnetic 3d and Dy III , because the latter kind of complexes has weak magnetic couplings between paramagnetic 3d and Dy III , which result in a small energy separation between the ground state and the first and/or higher excited states.…”

“…Among the Dy­(III)-based SMMs, Zn–Dy heterometallic complexes have received increasing attention, ,− which could mainly be ascribed to the following several reasons. The first reason is that the saturated d 10 electronic configuration can prevent the quenching of Dy III luminescence, which favors the Zn–Dy complexes exhibiting luminescence and SMM multifunctional properties. ,, The second reason is that magnetic coupling between Zn II and Dy III ions can be eliminated.…”

“…Among the Dy­(III)-based SMMs, Zn–Dy heterometallic complexes have received increasing attention, ,− which could mainly be ascribed to the following several reasons. The first reason is that the saturated d 10 electronic configuration can prevent the quenching of Dy III luminescence, which favors the Zn–Dy complexes exhibiting luminescence and SMM multifunctional properties. ,, The second reason is that magnetic coupling between Zn II and Dy III ions can be eliminated. This leads to the SMM performance of Zn–Dy complexes superior to the complexes containing paramagnetic 3d and Dy III , because the latter kind of complexes has weak magnetic couplings between paramagnetic 3d and Dy III , which result in a small energy separation between the ground state and the first and/or higher excited states. , Additionally, the presence of diamagnetic Zn II introduces an internal dilution effect that can diminish the intermolecular interactions and, in turn, the quantum tunneling of magnetization (QTM), resulting in the improvement of SMM behavior of Zn–Dy complexes .…”

Heterometallic ZnII–LnIII–ZnII Schiff Base Complexes with Linear or Bent Conformation—Synthesis, Crystal Structures, Luminescent and Magnetic Characterization

“…The ligand molecules with 1,3-diamino-2-propanol bridge may undergo double or triple deprotonation forming N 2 O 2 or N 2 O 3 coordination pockets ( Table S1 ). The doubly deprotonated ligands form classic mono- up to tetranuclear coordination compounds [ 11 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. But only the triple deprotonation enables the higher nuclearity of complexes: to hexa- [ 22 , 30 ] and heptanuclear units [ 31 ] with the use of additional anions such as nitrate or acetate.…”