共查询到20条相似文献,搜索用时 15 毫秒
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(38):11603-11607
Abstraction of a chloride ligand from the dysprosium metallocene [(Cpttt)2DyCl] ( 1Dy Cpttt=1,2,4‐tri(tert ‐butyl)cyclopentadienide) by the triethylsilylium cation produces the first base‐free rare‐earth metallocenium cation [(Cpttt)2Dy]+ ( 2Dy ) as a salt of the non‐coordinating [B(C6F5)4]− anion. Magnetic measurements reveal that [ 2Dy ][B(C6F5)4] is an SMM with a record anisotropy barrier up to 1277 cm−1 (1837 K) in zero field and a record magnetic blocking temperature of 60 K, including hysteresis with coercivity. The exceptional magnetic axiality of 2Dy is further highlighted by computational studies, which reveal this system to be the first lanthanide SMM in which all low‐lying Kramers doublets correspond to a well‐defined MJ value, with no significant mixing even in the higher doublets. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(43):13601-13605
Meeting the challenges of Moore's Law, predicting ambitious miniaturization rates of integrated circuits, requires to go beyond the traditional top‐down approaches, and to employ synthetic chemistry methods, to use bottom‐up techniques. During the recent decades, it has been shown that open‐shell coordination compounds may exhibit intramolecular spontaneous magnetization, thus offering promising prospects for storage and processing of digital information. Against this background we regarded it rewarding to implement similar magnetic centers into a ceramic material, which would provide better long‐term mechanical and chemical durability. Here we present new robust inorganic compounds containing separate DyO+ ions in an apatite matrix, which behave like single‐molecule magnets. The materials exhibit a blocking temperature of 11 K and an energy barrier for spin reversal of a thousand inverse centimeters which is among the highest values ever achieved. 相似文献
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Angelos B. Canaj Sourav Dey Emma Regincs Martí Claire Wilson Gopalan Rajaraman Mark Murrie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14284-14289
Following a novel synthetic strategy where the strong uniaxial ligand field generated by the Ph3SiO? (Ph3SiO?=anion of triphenylsilanol) and the 2,4‐di‐tBu‐PhO? (2,4‐di‐tBu‐PhO?=anion of 2,4‐di‐tertbutylphenol) ligands combined with the weak equatorial field of the ligand LN6 , leads to [DyIII(LN6)(2,4‐di‐tBu‐PhO)2](PF6) ( 1 ), [DyIII(LN6)(Ph3SiO)2](PF6) ( 2 ) and [DyIII(LN6)(Ph3SiO)2](BPh4) ( 3 ) hexagonal bipyramidal dysprosium(III) single‐molecule magnets (SMMs) with high anisotropy barriers of Ueff=973 K for 1 , Ueff=1080 K for 2 and Ueff=1124 K for 3 under zero applied dc field. Ab initio calculations predict that the dominant magnetization reversal barrier of these complexes expands up to the 3rd Kramers doublet, thus revealing for the first time the exceptional uniaxial magnetic anisotropy that even the six equatorial donor atoms fail to negate, opening up the possibility to other higher‐order symmetry SMMs. 相似文献
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Lena Scherthan Sebastian F. M. Schmidt Hendrik Auerbach Tim Hochdrffer Juliusz A. Wolny Wenli Bi Jiyong Zhao Michael Y. Hu Tom Toellner E. Ercan Alp Dennis E. Brown Christopher E. Anson Annie K. Powell Volker Schünemann 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(11):3482-3487
Time‐domain synchrotron Mössbauer spectroscopy (SMS) based on the Mössbauer effect of 161Dy has been used to investigate the magnetic properties of a DyIII‐based single‐molecule magnet (SMM). The magnetic hyperfine field of [Dy(Cy3PO)2(H2O)5]Br3?2 (Cy3PO)?2 H2O?2 EtOH is with B0=582.3(5) T significantly larger than that of the free‐ion DyIII with a 6H15/2 ground state. This difference is attributed to the influence of the coordinating ligands on the Fermi contact interaction between the s and 4f electrons of the DyIII ion. This study demonstrates that 161Dy SMS is an effective local probe of the influence of the coordinating ligands on the magnetic structure of Dy‐containing compounds. 相似文献