Magnetic Relaxation Studies on Trigonal Bipyramidal Cobalt(II) Complexes.,Chemistry - An Asian Journal

当前位置： X-MOL 学术 › Chem. Asian J. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Magnetic Relaxation Studies on Trigonal Bipyramidal Cobalt(II) Complexes.
Chemistry - An Asian Journal ( IF 3.5 ) Pub Date : 2020-01-16 , DOI: 10.1002/asia.201901511
Feng Shao _{1,

2,

3} , Benjamin Cahier _{1,

4} , Yi-Ting Wang _{1,

2} , Feng-Lei Yang _{1,

2,

5} , Eric Rivière ₁ , Régis Guillot ₁ , Nathalie Guihéry ₆ , Jia-Ping Tong _{2,

7} , Talal Mallah ₁

Affiliation

We report the preparation and the full characterization of a novel mononuclear trigonal bipyramidal CoII complex [Co(NS3 iPr )Br](BPh4 ) (1) with the tetradentate sulfur-containing ligand NS3 iPr (N(CH2 CH2 SCH(CH3 )2 )3 ). The comparison of its magnetic behaviour with those of two previously reported compounds [Co(NS3 iPr )Cl](BPh4 ) (2) and [Co(NS3 tBu )Br](ClO4 ) (3) (NS3 tBu =N(CH2 CH2 SC(CH3 )3 )3 ) with similar structures shows that 1 displays a single-molecule magnet behaviour with the longest magnetic relaxation time (0.051 s) at T=1.8 K, which is almost thirty times larger than that of 3 (0.0019 s) and more than three times larger than that of 2 (0.015 s), though its effective energy barrier (26 cm-1 ) is smaller. Compound 1, which contains two crystallographically independent molecules, presents smaller rhombic parameters (E=1.45 and 0.59 cm-1 ) than 2 (E=2.05 and 1.02 cm-1 ) and 3 (E=2.00 and 0.80 cm-1 ) obtained from theoretical calculations. Compounds 2 and 3 have almost the same axial (D) and rhombic (E) parameter values, but present a large difference of their effective energy barrier and magnetic relaxation which may be attributed to the larger volume of BPh4 - than ClO4 - leading to larger diamagnetic dilution (weaker magnetic dipolar interaction) for 2 than for 3. The combination of these factors leads to a much slower magnetic relaxation for 1 than for the two other compounds.

中文翻译：

三角双锥钴（II）配合物的磁弛豫研究。

我们报告的新型四核含硫配体NS3 iPr（N（CH2 CH2 SCH（CH3）2）的新型单核三角双锥双CoII复合物[Co（NS3 iPr）Br]（BPh4）（1） 3）。与之前报道的两种化合物[Co（NS3 iPr）Cl]（BPh4）（2）和[Co（NS3 tBu）Br]（ClO4）（3）的磁性比较（NS3 tBu = N（CH2 CH2具有相似结构的SC（CH3）3）3）显示1在T = 1.8 K时显示的单分子磁体行为具有最长的磁弛豫时间（0.051 s），几乎是3（0.0019 s）的三十倍），但其有效能垒（26 cm-1）较小，但大于2的三倍（0.015 s）。化合物1包含两个晶体学独立的分子，具有较小的菱形参数（E = 1.45和0。从理论计算获得的2（E = 2.05和1.02 cm-1）和3（E = 2.00和0.80 cm-1）比59 cm-1）大。化合物2和3的轴向（D）和菱形（E）参数值几乎相同，但化合物的有效能垒和磁弛豫差异很大，这可能归因于BPh4的体积比ClO4的体积大，导致BPh4的体积更大抗磁性稀释（较弱的磁偶极相互作用）为2时比3稀释。这些因素的组合导致1的磁弛豫要比其他两种化合物慢得多。

更新日期：2020-01-16

点击分享查看原文

点击收藏

阅读更多本刊最新论文