Structural and Magnetization Dynamics of Borohydride-Bridged Rare-Earth Metallocenium Cations.
Structural and Magnetization Dynamics of Borohydride-Bridged Rare-Earth Metallocenium Cations.
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DOI：
10.1021/acs.inorgchem.3c01038
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发表时间：
2023-06-26
影响因子：
4.6
通讯作者：
Layfield, Richard A.
中科院分区：
文献类型：
--
作者：
Price, Christopher G. T.;Mondal, Arpan;Durrant, James P.;Tang, Jinkui;Layfield, Richard A.
报道了双金属硼氢化物桥接的异戊二烯化合物[{(η - 5-Cpttt)(η - 5-CpMe4t)Dy}2(μ:κ2:κ2- bh4)]+[B(C6F5)4]−([3Dy][B(C6F5)4])的结构和磁性，以及同结构的钇和镥类似物（Cpttt为1,2,4-三（叔丁基）环戊二烯基，CpMe4t为四甲基（叔丁基）环戊二烯基）的液相动力学。[3M][B(C6F5)4]是由[(η5-Cpttt)(η5-CpMe4t)Dy(BH4)] （2M）与[CPh3][B(C6F5)4]以2:1的化学计量反应合成的，半夹心配合物[(η5-Cpttt)M(BH4)2(THF)] (1M) （M = Y, Dy, Lu）与NaCpMe4t反应得到茂金属2M。晶体学研究表明M··B在1M、2M和3M系列中移动时距离显著延长，在3M中基本呈线性的{M··B···M}桥。多核核谱分析表明，Cpttt配体在3Y和3Lu溶液中的旋转受限。[3M][B(C6F5)4]的单分子磁体（SMM）性质由拉曼和奥巴赫过程表征，有效势垒为533(18)cm-1，并通过二激Kramers双重态弛豫。虽然在[3M][B(C6F5)4]中没有观察到磁化的量子隧穿（QTM），但令人惊讶的是，在其磁稀释版本中发现了它，它具有非常相似的Ueff = 499(21) cm-1的势垒。与这一观察结果一致的是，在2k处发现[3M][B(C6F5)4]的磁滞回线开口略宽，但稀释的类似物则没有。利用多参考从头算解释了镝smm的动态磁性和交换相互作用在3Dy中的作用。报道了一种双金属硼氢化物桥接镝单分子磁体的结构和动态磁性能，并用从头算方法进行了解释。该化合物的磁弛豫表现为拉曼过程和奥巴赫过程，后者的势垒为533(18)cm−1。磁稀释引入QTM作为低温下的主要弛豫过程。还描述了同结构钇和镥类似物的固相动力学。
The structure and magnetic properties of the bimetallic borohydride-bridged dysprosocenium compound [{(η5-Cpttt)(η5-CpMe4t)Dy}2(μ:κ2:κ2-BH4)]+[B(C6F5)4]− ([3Dy][B(C6F5)4]) are reported along with the solution-phase dynamics of the isostructural yttrium and lutetium analogues (Cpttt is 1,2,4-tri(tert-butyl)cyclopentadienyl, CpMe4t is tetramethyl(tert-butyl)cyclopentadienyl). The synthesis of [3M][B(C6F5)4] was accomplished in the 2:1 stoichiometric reactions of [(η5-Cpttt)(η5-CpMe4t)Dy(BH4)] (2M) with [CPh3][B(C6F5)4], with the metallocenes 2M obtained from reactions of the half-sandwich complexes [(η5-Cpttt)M(BH4)2(THF)] (1M) (M = Y, Dy, Lu) with NaCpMe4t. Crystallographic studies show significant lengthening of the M···B distance on moving through the series 1M, 2M, and 3M, with essentially linear {M···B···M} bridges in 3M. Multinuclear NMR spectroscopy indicates restricted rotation of the Cpttt ligands in 3Y and 3Lu in solution. The single-molecule magnet (SMM) properties of [3M][B(C6F5)4] are characterized by Raman and Orbach processes, with an effective barrier of 533(18) cm–1 and relaxation via the second-excited Kramers doublet. Although quantum tunneling of the magnetization (QTM) was not observed for [3M][B(C6F5)4], it was, surprisingly, found in its magnetically dilute version, which has a very similar barrier of Ueff = 499(21) cm–1. Consistent with this observation, slightly wider openings of the magnetic hysteresis loop at 2 K are found for [3M][B(C6F5)4] but not for the diluted analogue. The dynamic magnetic properties of the dysprosium SMMs and the role of exchange interactions in 3Dy are interpreted with the aid of multireference ab initio calculations. The structure and dynamic magnetic properties of a bimetallic borohydride-bridged dysprosocenium single-molecule magnet are reported and interpreted with the aid of ab initio calculations. The magnetic relaxation in this compound is characterized by Raman and Orbach processes, the latter with a barrier of 533(18) cm−1. Magnetic dilution introduces QTM as the dominant relaxation process at low temperatures. The solution-phase dynamics of the isostructural yttrium and lutetium analogues are also described.
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影响因子：
64.8
作者：
Goodwin, Conrad A. P.;Ortu, Fabrizio;Mills, David P.
通讯作者：
Mills, David P.
影响因子：
15
作者：
Briganti M;Lucaccini E;Chelazzi L;Ciattini S;Sorace L;Sessoli R;Totti F;Perfetti M
通讯作者：
Perfetti M
影响因子：
8.4
作者：
Gysler M;El Hallak F;Ungur L;Marx R;Hakl M;Neugebauer P;Rechkemmer Y;Lan Y;Sheikin I;Orlita M;Anson CE;Powell AK;Sessoli R;Chibotaru LF;van Slageren J
通讯作者：
van Slageren J
三金属镝茂金属阳离子的合成及单分子磁体性能
DOI：
10.1039/d1cc02139g
发表时间：
2021-06-29
期刊：
Chemical communications (Cambridge, England)
影响因子：
--
作者：
He M;Guo FS;Tang J;Mansikkamäki A;Layfield RA
通讯作者：
Layfield RA
影响因子：
4.6
作者：
Guo, Fu-Sheng;He, Mian;Huang, Guo-Zhang;Giblin, Sean R.;Billington, David;Heinemann, Frank W.;Tong, Ming-Liang;Mansikkamaki, Akseli;Layfield, Richard A.
通讯作者：
Layfield, Richard A.