Effect of the Transition Metal Ions on the Single-Molecule Magnet Properties in a Family of Air-Stable 3d–4f Ion-Pair Compounds with Pentagonal Bipyramidal Ln(III) Ions

Abstract

Single-molecule magnets (SMMs) are expected to be promising candidates for the applications of high-density information storage materials and quantum information processing. Lanthanide SMMs have attracted considerable interest in recent years due to their excellent performance. It has always been interesting but not straightforward to study the relaxation and blocking mechanisms by embedding 3d ions into 4f SMMs. Here we report a family of air-stable 3d–4f ion-pair compounds, YFe (1), DyCr (2), DyFe (3), DyCo (4), and Dy0.04Y0.96Fe (5), composed of pentagonal bipyramidal (D 5h ) LnIII cations and transition metallocyanate anions. The ion-pair nature makes the dipole–dipole interactions almost the only component of the magnetic interactions that can be clarified and analytically resolved under proper approximation. Therefore, this family provides an intuitive opportunity to investigate the effects of 3d–4f and 4f–4f magnetic interactions on the behavior of site-resolved 4f SMMs. Dynamic magnetic measurements of 1 under a 4 kOe external field reveal slow magnetic relaxation originating from the isolated [FeIII]LS (S = 1/2) ions. Under zero dc field, compounds 2–5 show similar magnetic relaxation processes coming from the separated pentagonal bipyramidal (D 5h ) DyIII ions with high Orbach barriers of 592(5), 596(4), 595(3), and 606(4) K, respectively. Comparatively, both compounds 3 and 5 exhibit two distinct relaxation processes, respectively from the [FeIII]LS and DyIII [U eff = 596(4) K for 3 and 610(7) K for 5] ions, under a 4 kOe dc field. The dipolar interactions between the neighboring TMIII (TM = transition metal, CrIII or [FeIII]LS) and DyIII ions were revealed to have little effect on the thermal relaxation in compounds 2, 3, and 5, or the coexistence of the two separate relaxation processes in compounds 3 and 5 under a 4 kOe dc field, but they significantly affect the quantum tunneling of magnetization and the magnetic hysteresis behavior of 2 and 3 at low temperatures compared to those of 4.

Interplay between anisotropy and magnetic exchange to modulate the magnetic relaxation behaviours of phenoxo bridged Dy2dimers with axial β-diketonate co-ligands

“…In accordance with the current literature review, it emerges that multidentate Schiff base ligands with distinct coordination environments have been effectively applied in the assembly of polynuclear heterometallic 3d/4f 61–75 and homometallic 4f complexes. 57,76–85 Utilizing the above-mentioned knowledge, we have applied ( E )-2-((pyridin-2-ylmethylene)amino)phenol (LH) in order to construct homometallic lanthanide complexes.…”

Photo‐responsive Single‐Molecule Magnet Showing 0D to 1D Single‐Crystal‐to‐Single‐Crystal Structural Transition and Hysteresis Modulation

“…The profiles of lnτ vs. T À 1 can be best fitted to the equation containing Raman and Orbach processes. [27] The parameters are U eff /k B = 279 K and τ 0 = 6.56 × 10 À 11 s, C = 1.09 10 À 5 K À 5.5 s À 1 , n = 6.27, for 1Dy@Y, and U eff /k B = 206 K and τ 0 = 8.31 × 10 À 11 s, C = 2.67 × 10 À 4 K À 5.74 s À 1 , n = 5.74 for 2Dy@Y (Table 2). The ESDs are again found to be significant (Figure S28, Table S8).…”

From dinuclear to two-dimensional Dy(iii) complexes: single crystal–single crystal transformation and single-molecule magnetic behavior

“…Single-molecule magnets (SMMs) [1][2][3] as one of the significant branches of magnetic bistable materials have potential applications in high-density information storage, quantum computing, and molecular spintronics. [4][5][6] The research on SMMs mainly focuses on transition metal ions, [7][8][9][10] lanthanide ions, [11][12][13][14][15] and 3d-4f heterometallic ions, [16][17][18] among which the Dy 3+ -based SMMs are especially conspicuous since the characteristic large spin quantum numbers and unquenched orbital angular momentum of Dy 3+ result in strong spin-orbit coupling and magnetic anisotropy that SMMs require. In recent decades, great efforts have been made to develop strategies for constructing SMMs with high effective energy barriers (U eff ) and blocking temperatures (T B ), [19][20][21] which are the primary performance indicators for SMMs.…”