On balancing the QTM and the direct relaxation processes in single-ion magnets – the importance of symmetry control

Deng, Yi‐Fei; Han, Tian; Yin, Bing; Zheng, Yan‐Zhen

doi:10.1039/c7qi00135e

Cited by 55 publications

(35 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Direct process contributes to fast relaxation and thus it will reduce the phenomenological U eff values. In fact, the importance of the balance between QTM and the direct process in field‐induced SIM has already been demonstrated for some mononuclear Co II compounds of similar structures, in which others fail to achieve slow relaxation with an applied field even up to 7000 Oe . Conversely, in the case of 2′ , which is a zero‐field SIM, there is no need for the external field and thus the direct process is practically negligible.…”

Section: Resultsmentioning

confidence: 99%

“…Similarly, the sum of the contributions of the five equatorial atoms could represent the equatorial electrostatic potential, denoted as ESP(equ). It should be admitted that this analysis on the electrostatic potential is preliminary, but useful insight could be obtained from it as already shown in our previous study on some Dy III SIMs . As shown in Table , the ESP(equ)/ESP(ax) ratio of 2′ is 0.472 which is significantly smaller than 1.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal Dy^III Single‐Ion Magnets

Yang

et al. 2017

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

Taking advantage of the steric hindrance and charge-driving effects, four air-stable pentagonal bipyramidal mononuclear Dy compounds were hydrothermally synthesized. With a tetradentate ligand, N,N'-bis(2-methylenepyridinyl)ethylenediamine (Bpen), invariably coordinates to Dy in an equatorial plan, 1-3 achieve an orderly transformation of the ligand field by sequentially replacing the remaining sites of the Dy ion. Compound 4 possesses the same coordination atoms but a different peripheral coordination sphere with 3. Magnetic characterizations display that the compounds are field-induced single-ion magnets (SIM) with actually low barriers, even though 2 has both the same atoms and a similar geometry of the first sphere compared with [Dy(bbpen)Cl] (2', H bbpen=N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-methylpyridyl)ethylenediamin), a high-performance SIM previously reported. Detailed ab initio calculations have been employed to further elucidate the electronic and magnetic structure of the low-lying energy levels of compounds 1-4 and 2'. The theoretical results indicate there is an apparent difference in the electronic structure for these compounds. The analysis on the electrostatic potential further demonstrates that although the pentagonal bipyramidal D is one of the ideal configurations expected, the electron density of the donor atoms from the different hybridizations and other functional groups, outside the first sphere, should also be considered in the rational design of promising molecular magnets.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal Dy^III Single‐Ion Magnets

Yang

et al. 2017

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Interestingly, the same group reported two Co II three‐coordinated species with a {CoO 3 } core: [Na(THF) 6 ][Co(Oar) 3 ] ( 41 ) and [(THF) 3 NaCo(Oar) 3 ] ( 42 ), which exhibit negative D parameters of −103 cm −1 ( D fit =−85 cm −1 ) and −98 cm −1 ( D fit =−80 cm −1 ) obtained from NEVPT2 calculations (see Figure 7 c). [47] Perceiving these exciting results, further exploration is required in this category of complexes to understand the magnetic anisotropy deeper.…”

Section: Zero‐field Splitting In Transition Metal‐based Simsmentioning

confidence: 99%

Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in Fe^II, Co^II, and Ni^II Single‐Ion Magnets

Sarkar

Dey

Rajaraman

2020

Chemistry A European J

101

View full text Add to dashboard Cite

Since the last decade, the focus in the area of single‐molecule magnets (SMMs) has been shifting constructively towards the development of single‐ion magnets (SIMs) based on transition metals and lanthanides. Although ground‐breaking results have been witnessed for DyIII‐based SIMs, significant results have also been obtained for some mononuclear transition metal SIMs. Among others, studies based on CoII ion are very prominent as they often exhibit high magnetic anisotropy or zero‐field splitting parameters and offer a large barrier height for magnetisation reversal. Although CoII possibly holds the record for having the largest number of zero‐field SIMs known for any transition metal ion, controlling the magnetic anisotropy in these systems are is still a challenge. In addition to the modern spectroscopic techniques, theoretical studies, especially ab initio CASSCF/NEVPT2 approaches, have been used to uncover the electronic structure of various CoII SIMs. In this article, with some selected examples, the aim is to showcase how varying the coordination number from two to eight, and the geometry around the CoII centre alters the magnetic anisotropy. This offers some design principles for the experimentalists to target new generation SIMs based on the CoII ion. Additionally, some important FeII/FeIII and NiII complexes exhibiting large magnetic anisotropy and SIM properties are also discussed.

show abstract

“…[29] However, magnetic relaxation mechanism is still under studies since many features of the relaxation dynamics are not known. More detailed studies of magnetic Ln III compounds are necessary to understand the dynamic of the relaxation process and the different mechanisms involved [16,18,28,[30][31][32] (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Role of the Templating Heteroatom on Both Structural and Magnetic Properties of POM‐Based SIM Lanthanoid Complexes

et al. 2021

View full text Add to dashboard Cite

The plasticity of the coordination chemistry of Lanthanoid ions (LnIII) has allow the design of novel coordination compounds with slow relaxation of the magnetization since the first Single Ion Magnet (SIMs) was reported by Ishikawa, who used the phthalocyaninate ligand to make a “sandwich type” complex. The coordination chemistry has allowed the possibility to design different types of molecular complexes with SIMs behaviour based on organic ligands. There is also SIMs based on inorganic ligands, using different types of lacunary polyoxometalates (LPOM) like, [XW11O39]n−. The combination of both types of ligands can produce hybrid inorganic‐organic LnIII complexes with SIM behaviour. This is an attractive approach since these hybrid materials could benefit from the combination of the ease of functionalization of the organic ligands with the robustness of the inorganic moieties. There are reports that a hybrid mononuclear DyIII complex could improve the relaxation dynamics when it is compared to the inorganic analogues. Thus, in this review we present a study and comparison on the improvement that inorganic and organic ligands can cause to the geometry of the metal centres of fully inorganic and hybrid (mononuclear and dinuclear) lanthanoid complexes (for DyIII, ErIII and YbIII). Moreover, we will discuss which of these changes can modify the magnetic properties of the Lanthanoid Complexes.

show abstract

On balancing the QTM and the direct relaxation processes in single-ion magnets – the importance of symmetry control

Abstract: Two mononuclear trigonal-planar Co(ii) complexes with a similar coordination environment except for the symmetries were reported to exhibit distinct relaxation dynamics due to the effect of the QTM and direct process.

Cited by 55 publications

References 51 publications

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal Dy^III Single‐Ion Magnets

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal Dy^III Single‐Ion Magnets

Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in Fe^II, Co^II, and Ni^II Single‐Ion Magnets

Role of the Templating Heteroatom on Both Structural and Magnetic Properties of POM‐Based SIM Lanthanoid Complexes

Contact Info

Product

Resources

About

On balancing the QTM and the direct relaxation processes in single-ion magnets – the importance of symmetry control

Abstract: Two mononuclear trigonal-planar Co(ii) complexes with a similar coordination environment except for the symmetries were reported to exhibit distinct relaxation dynamics due to the effect of the QTM and direct process.

Cited by 55 publications

References 51 publications

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal DyIII Single‐Ion Magnets

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal DyIII Single‐Ion Magnets

Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in FeII, CoII, and NiII Single‐Ion Magnets

Role of the Templating Heteroatom on Both Structural and Magnetic Properties of POM‐Based SIM Lanthanoid Complexes

Contact Info

Product

Resources

About

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal Dy^III Single‐Ion Magnets

Experimental and Theoretical Interpretation on the Magnetic Behavior in a Series of Pentagonal‐Bipyramidal Dy^III Single‐Ion Magnets

Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in Fe^II, Co^II, and Ni^II Single‐Ion Magnets