Single-molecule magnet behavior in a Cu^II-decorated {DyIII2} complex with nitronyl nitroxide biradicals

Abstract

Unprecedented octa-spin-center 2p–3d–4f compounds were obtained using a specially designed nitronyl nitroxide biradical, where the Dy analogue exhibited SMM behavior.

Terbium Triangle Bridged by a Triazole Nitronyl Nitroxide Radical with Single-Molecule-Magnet Behavior

“…The plot of ln τ versus T –1 exhibits linear correlation, which indicates that the magnetic spin was reversed by a thermally activated Orbach mechanism process (Figure b) . With the help of the Arrhenius equation [τ = τ 0 exp­(Δ eff / k B T )], an effective energy gap of 14 K and a preexponential τ 0 of 3.1 × 10 –7 s were obtained, which are consistent with those of the reported SMMs. ,,,− ,− In addition, on the basis of the frequency dependence of the ac susceptibility data, Cole–Cole plots (χ″ versus χ′) with nearly semicircular shapes were obtained (Figure S11). With the help of a generalized Debye model, the distribution coefficient α was fitted, and the value was in the range of 0.39–0.28 (between 2 and 3.2 K), which indicates a narrow distribution of the magnetization relaxation time.…”

A high-spin diradical dianion and its bridged chemically switchable single-molecule magnet

“… 13 In the studied diradical-containing SMMs, the diradicals are mainly composed of neutral bis(imino nitroxide) moieties. 14 However, neutral diradicals often suffer from weak coordination to metal ions. In recent years, a few stable triplet ground state diradicals with Δ E ST over 298 K have been realized by electron delocalization and steric protection strategies.…”

Two Octanuclear {Cu4Ln4} (Ln = Dy or Tb) Complexes with a Butterfly-Shaped Unit Exhibiting Zero-Field Single-Molecule Magnet Behavior

“…In 2004, Osa and co-workers reported a tetranuclear [Cu II LTb III (hfac) 2 ] 2 complex, which was the first 3d–4f heteronuclear SMM with an energy barrier ( U eff ) of 21 K . So far, a great diversity of Cu–Ln SMMs with different nuclearities and structures have been described. − (Table S1). Nevertheless, designing an appropriate ligand as a “bridge” to associate 3d ions with 4f ions is still a huge challenge.…”