Anisotropic exchange interaction and field-induced SMM behaviour in a mixed valence {CoII4CoIII2} complex

Abstract

We report a combined computational and experimental study of SMM behaviour in a mixed valent {CoIII2CoII4} complex with anisotropic exchange interactions.

Two Heterometallic Nanoclusters [DyIII4NiII8] and [DyIII10MnIII4MnII2]: Structure, Assembly Mechanism, and Magnetic Properties

“…However, no suitable external field was found for 2 to suppress its quantum tunneling; thus, a 0 dc field was also used for further dynamic magnetic measurements in the frequency of 0−10000 Hz for 2. 62,63 These measurements revealed significant temperature and frequency dependences in their ac magnetic susceptibilities, which unambiguously demonstrated the existence of slow magnetic relaxation behavior in both title heterometallic ). 64,65 As shown in Figure S31e, attempts to simulate the ln(τ/s) versus T −1 plot on the basis of eq 1 by neglecting the last term gave the parameters τ 0 = [6.21( 2…”

“…They revealed optimum dc fields of 1000 and 0 Oe for 1 and 2 , respectively. However, no suitable external field was found for 2 to suppress its quantum tunneling; thus, a 0 dc field was also used for further dynamic magnetic measurements in the frequency of 0–10000 Hz for 2 . , These measurements revealed significant temperature and frequency dependences in their ac magnetic susceptibilities, which unambiguously demonstrated the existence of slow magnetic relaxation behavior in both title heterometallic nanoclusters, as seen from Figure c,d and Figures S31a,b, S32, and S33.…”

One-Dimensional CoII and NiII Helical Coordination Polymers Exhibiting Zero-Field Splitting

“…Nevertheless, at 2 kOe dc field, frequencies dependent on both in-phase (χ m ′) and out-of-phase (χ m ″) signals were observed below 4 K, associated with field-induced SMM behavior (Figure ). Also, the ln τ vs T –1 plot (Figure S6) suggests a linear dependence, suggesting a thermally activated Orbach relaxation process, with a barrier of U eff = 11.7 cm –1 . In the case of 2 , non-out-of-phase magnetic susceptibility was observed at both applied fields (0 and 2 kOe).…”

A dinuclear Co(iii)/Co(ii) complex based on the H2pmide ligand showing field-induced SMM behaviour

“…As observed in these Co pivalate systems, chelating ligands with N donor atoms strongly favour Co(II) to Co(III) air oxidation, frequently affording mixed-valence complexes. [37][38][39][40][41][42][43][44][45][46][47] The complex crystallizes in a P2 1 /n monoclinic cell with the entire molecule as the asymmetric unit and without any crystallization solvent molecule.…”