The near-infrared luminescence and magnetism of dinuclear complexes with different local symmetries constructed from a β-diketonate co-ligand and bis-Schiff base ligand

Abstract

A DyIII-complex based on a β-diketonate co-ligand and bi-Schiff base ligand displays slow magnetic relaxation behavior.

Slow magnetic relaxation in dinuclear dysprosium and holmium phenoxide bridged complexes: a Dy2single molecule magnet with a high energy barrier

“…22,23 25 indicate that the geometry is closer to a triangular dodecahedron, but highly distorted towards a square antiprismatic geometry in all cases (Table S2). The main distances and angles about the metal centres agree with those expected for dysprosium or holmium complexes with polydentate N,O donors, [26][27] and this aspect does not deserve further consideration. Nevertheless, it should be remarked that the bond distances and angles in Dy2•2THF and Dy2•2Py are very similar, if we take into account the standard deviations, thus suggesting that the solvates do not exert a significant influence on the geometric parameters.…”

Design of Heterometallic {LnIII–MV} (Ln = Dy, Er; M = W, Mo) Molecular Nanomagnets: Protonation Induced Structural Diversification

“…The Dy2–N and Dy2–O bond lengths are similar to those around the Dy1 ion, falling in the range of 2.488(4)–2.585(4) Å and 2.332(3)–2.452(3) Å, respectively. Note that different from the most reported β-diketonate-based lanthanide complexes, one of the carbonyl oxygen atoms in L – ligand serves as a bridge. − As a consequence, the two Dy III ions in asymmetric unit are connected by three oxygen bridges (O4, O5, O6) with a Dy···Dy distance of 3.702 Å. It is worth mentioning that the bond length of Dy1–O1 is the shortest (2.314(3) Å), which would play an important role in mediating the magnetic anisotropy of 1 DyW .…”

“…However, lanthanide ions tend to adopt high coordination numbers with “hard” oxygen-containing ligands, which often leads to the rapid coordination saturation by solvent molecules rather than the coordination with nitrogen-containing octacyanometallate building units. A feasible approach is using multidentate ligands to modify the coordination sphere of lanthanide ions so as to allow the preorientated coordination with the nitrogen atoms from octacyanometallate building units. − β-Diketone, a well-known bidentate ligand, has been widely used in the construction of luminescent materials. , It can also help to stabilize the Ising ground state of Dy III ion in a certain molecular geometry. Thus, a series of Dy-β-diketone ligands have been extensively used to construct Dy III –SMMs through regulation of the auxiliary ligands. − However, studies on cyano-bridged systems containing β-diketonate-ligated lanthanide units have not been reported.…”

“…A feasible approach is using multidentate ligands to modify the coordination sphere of lanthanide ions so as to allow the preorientated coordination with the nitrogen atoms from octacyanometallate building units. − β-Diketone, a well-known bidentate ligand, has been widely used in the construction of luminescent materials. , It can also help to stabilize the Ising ground state of Dy III ion in a certain molecular geometry. Thus, a series of Dy-β-diketone ligands have been extensively used to construct Dy III –SMMs through regulation of the auxiliary ligands. − However, studies on cyano-bridged systems containing β-diketonate-ligated lanthanide units have not been reported. In view of this, we intend to construct such kinds of {Ln III –M V } systems and investigate their nanomagnet properties.…”

Visible and NIR emitting Yb(iii) and Er(iii) complexes sensitized by β-diketonates and phenanthroline derivatives

“…where s Ln is the observed lifetime and s Rad is the typical radiative lifetime of the lanthanide ions. Usually, for the emission at 1550 nm from Er(III) ions, the radiative lifetime is about 14 000 28,29,31,[36][37][38][39][40][41] ms, and for the emission at 980 nm of Yb(III) ions, this value is about 2000 ms. 28,42,43 Respect to the Er(III) ions, the obtained values for the intrinsic quantum yield are similar to values obtained in other azaciclo-diketonate complexes. 28,29,31,[38][39][40]43 However, for the Yb(III) the values span in a wider range.…”