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Regulating the slow magnetic relaxation behavior of two different shapes Dy 4 clusters with in situ formed penta‐ and heptadentate Schiff base ligands
Author(s) -
Zhu ZhongHong,
Wang HaiLing,
Fu XiaoXiao,
Zou HuaHong,
Liang FuPei
Publication year - 2020
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.5808
Subject(s) - chemistry , ligand (biochemistry) , schiff base , denticity , aldehyde , cluster (spacecraft) , chelation , crystallography , ion , propanol , molecule , dysprosium , medicinal chemistry , stereochemistry , catalysis , crystal structure , ethanol , inorganic chemistry , organic chemistry , biochemistry , receptor , computer science , programming language
The design and synthesis of clusters possessing the same number of cores but different connection methods and properties have always been difficult. Herein, we used 2‐pyridinaldehyde, 1,3‐diamino‐2‐propanol, and Dy (ClO 4 ) 3 ·6H 2 O at room temperature (RT) to obtain the cluster [Dy 4 (L 1 ) 4 ( μ 2 ‐OH) 4 ]·4ClO 4 − ( 1 , HL 1 = 2‐pyridinecarboxaldehyde‐1,3‐diamino‐2‐propanol) with square Dy 4 O 8 cluster cores. Cluster 1 consisted of four Schiff base ligands (L 1 ) − , four Dy(III) ions, four bridged ( μ 2 ‐OH) − , and four free ClO 4 − . The ligand HL 1 was formed by in situ Schiff base reaction with 2‐pyridinecarbaldehyde and 1,3‐diamino‐2‐propanol in the presence of Dy(III) ions. 2‐Aldehyde‐8‐hydroxyquinoline, 1,3‐diamino‐2‐propanol, and Dy (NO 3 ) 3 ·6H 2 O reacted at RT to yield a tetranuclear Dy(III) cluster [Dy 4 (L 2 ) 2 ( μ 3 ‐OH) 2 (NO 3 ) 4 (EtOH) 2 ]·2CH 3 CN ( 2 , H 3 L 2 = 2‐aldehyde‐8‐hydroxyquinoline‐1,3‐diamino‐2‐propanol) with butterfly‐shaped Dy 4 O 6 cluster core. Cluster 2 consisted of two ligands (L 2 ) 3− , four Dy(III) ions, two bridged μ 3 ‐OH, two end‐group‐coordinated ethanol molecules, and four bidentate‐chelated NO 3 − . The in situ reaction of 2‐aldehyde‐8‐hydroxyquinoline and 1,3‐diamino‐2‐propanol under Dy(III) ion‐assisted catalytic conditions provided the ligand H 3 L 2 . It is worth noting that the magnetic test showed that 1 is a typical single‐molecule magnet (SMM), whereas 2 only showed a significant frequency dependence behavior. We considered Orbach and Raman processes ( τ −1 = τ 0 −1 exp(− U eff / k B T ) + CT n ) to fit 1 and 2 in the high‐temperature range and obtained U eff = 7.01 and 5.43 K and τ 0 = 1.18 × 10 −4 and 4.14 × 10 −5 s, respectively.