Pentagonal Bipyramidal Ln(III) Complexes Containing an Axial Phosphine Oxide Ligand: Field-induced Single-ion Magnetism Behavior of the Dy(III) Analogues

Abstract

A series of neutral homologous complexes [(L)Ln(Cy 3 PO)Cl] {where Ln = Gd (1), Tb (2), Dy (3) and Er (5)} and [(L)Dy(Ph 3 PO)Cl] (4) [H 2 L = 2,6-diacetylpyridine bisbenzoylhydrazone] have been isolated. In these complexes, the central lanthanide ion possesses a pentagonal bipyramidal (PBP) geometry with an overall pseudo D 5h symmetry. The coordination environment around the lanthanide ion comprises of three nitrogen and two oxygen donors in an equatorial plane. The axial positions are taken up by a phosphine oxide (O donor) and a chloride ion. Among these compounds, the Dy(III) (3 and 4) analogues were found to be field-induced single-ion magnets.

Dysprosium Coordination Polymer Incorporating Dianthracene: Thermo‐induced Phase Transition Accompanied with Magnetic and Optical Changes

“…[24,25] In particular, complexes [(L)Dy III (R 3 PO)Cl] (R = cyclohexyl, phenyl) possess similar coordination geometries with that of 1-Dy except with an axial Cl atom, but their energy barriers are much higher (> 200 K). [26] We noticed that the axial For 2-Dy, the ac signals also emerge after applying an external dc field, but no maximum of out-of-phase susceptibility appears below 1 kHz (Figure 4d, S13), thus preventing the possibility of estimating energy barrier from Arrhenius law. Clearly, the magnetization relaxation is much faster in 2-Dy than that in 1-Dy.…”

A Series of Novel Pentagonal-Bipyramidal Erbium(III) Complexes with Acyclic Chelating N3O2 Schiff-Base Ligands: Synthesis, Structure, and Magnetism

“…This fact makes difficult the correct taking into account of the effects of the crystal packing for the charged moieties within the framework of the quantum chemical consideration of an isolated complex. Indeed, for the isostructural Dy analog of Complex 5 [55], there is also a not-so-good agreement between the energy of the first excited KD and the experimental estimation of the spin-reversal barrier, U eff .…”

“…For a Dy analog containing 95% of diamagnetic Y, the value of the magnetization barrier is 70 K under a low DC field, equal to 500 Oe. Despite the fact that the seven-coordinated PBP Dy complexes are being actively studied [33,34], we are aware of only three works in which the PBP Er complexes with pseudo-D 5h symmetry have been described [32,54,55]. Considering that Dy and Er have fundamentally different distributions of 4f electron density, oblate and prolate, respectively [35], it is of interest to synthesize PBP erbium complexes with acyclic pentadentate (N 3 O 2 ) ligands and to perform a comparative study of their SMM properties, depending on the nature of the axial ligands.…”

Halogen and Chalcogen Bonding Between the Triphenylphosphine Chalcogenides (Ph3P=E; E=O, S, Se) and Iodofluorobenzenes

“…Tricyclohexylphosphine oxide has been utilized as a ligand in single-ion, magnetic Dy(III) analogs, and triphenylphosphine oxide was reported to act as both a ligand and substrate for the Ir(III)-mediated synthesis of 3-aryl oxindoles. [17,18] Phosphine sulfide ligands have been reported in the preparation of Au(I) complexes as topoisomerase I inhibitors, luminescent cuprous coordination polymers, and fluorescent Ag(I) complexes. [19][20][21] In addition to halogen-and chalcogen interactions involving the chalcogen atoms, the triphenylphosphine chalcogenides can assemble via phenyl embracing, further influencing the resulting structures.…”

“…Like their parent phosphines, phosphine chalcogenides have seen wide‐ranging use as ligands for transition metal complexes, an application that is also strongly dependent on the electronic and steric environment around the chalcogen atom. Tricyclohexylphosphine oxide has been utilized as a ligand in single‐ion, magnetic Dy(III) analogs, and triphenylphosphine oxide was reported to act as both a ligand and substrate for the Ir(III)‐mediated synthesis of 3‐aryl oxindoles [17,18] . Phosphine sulfide ligands have been reported in the preparation of Au(I) complexes as topoisomerase I inhibitors, luminescent cuprous coordination polymers, and fluorescent Ag(I) complexes [19–21] .…”