2026-10-15T09:43:00Z https://api.figshare.com/v2/oai

oai:figshare.com:article/29673917 2026-01-08T16:02:57Z category_25108 category_25111 category_25129 portal_918 item_type_3 month_year_01_2026

Magnetic Hysteresis at 31 K in a Four-Coordinate Dysprosium(III) Amide Complex Benjamin Reant (9181130) John A. Seed (9181147) William J. A. Blackmore (11873154) Meagan Oakley (18246466) Conrad Goodwin (11850479) Nicolaj Kofod (6384143) Crystallography F-block chemistry Organometallic chemistry Dysprosium Single Molecule Magnet Amide Hysteresis Magnetic <p dir="ltr">Supporting data for: 10.1021/jacs.5c13255.</p><p dir="ltr">Contains raw files for: ATR-IR, Luminescence, NMR, PXRD, SQUID magnetometry, UV-Vis-NIR data, and processed SC-XRD data.</p><p dir="ltr">Manuscript abstract:</p><p dir="ltr">The state-of-the-art in single-molecule magnet (SMM) design is dominated by charged dysprosium sandwich complexes with mono- or dianionic π-ligands and which exhibit some of the highest open-loop magnetic hysteresis temperatures (<i>T</i>_H), the highest 100 s blocking temperatures (<i>T</i>_B100) and some of the largest barriers to magnetic reversal (<i>U</i>_eff). Architectures that leverage more charge-dense ligands, such as amides or alkoxides, with axial coordination and weak equatorial interactions can generate larger crystal fields (CFs), and hence larger <i>U</i>_eff values; however, this is often not accompanied by correspondingly high <i>T</i>_H or <i>T</i>_B100 values. Here we report a four-coordinate dysprosium(III) single-molecule magnet, [Dy{Me₂Si(NSi<i>i</i>Pr₃)₂}₂{K(toluene)₂}]_n (<b>1Dy</b>), with charge-dense amide donors, but a coordination environment that is between axial and tetrahedral in structure. Nevertheless, <b>1Dy</b> displays open-loop magnetic hysteresis up to 31 K using sweep rates of 22 Oe s^–1. The coercive field (<i>H</i>_C) is 1.65 T at 1.8 K, and <i>T</i>_B100 = 10.4 K. <i>Ab initio</i> calculations show the four-coordinate geometry imparts a strong axial CF as the ⁶H_15/2 spin-orbit multiplet is split over 1,958 K (1,361 cm^–1). The experimental <i>U</i>eff (742 K, 516 cm–1) is smaller and resides near the energy of the third excited Kramers doublet. <i>Ab initio</i> spin dynamics calculations show that the fitted barrier height at high T (>45 K) is 559 cm^–1. Non-Kramers ion analogues <b>1Tb</b> and <b>1Ho</b> show waist-restricted hysteresis and short relaxation times at all temperatures. The magnetic properties of <b>1Dy</b> place it highly amongst monometallic lanthanide SMMs using an alternative design strategy, which is synthetically simple and may be further refined.</p> 2026-01-08T16:02:57Z Dataset Dataset 10.48420/29673917.v1 https://figshare.com/articles/dataset/Magnetic_Hysteresis_at_31_K_in_a_Four-Coordinate_Dysprosium_III_Amide_Complex/29673917 CC BY 4.0