Mononuclear Single-Molecule Magnets: Tailoring the Magnetic Anisotropy of First-Row Transition-Metal Complexes

2013 ◽  
Vol 135 (18) ◽  
pp. 7010-7018 ◽  
Author(s):  
Silvia Gomez-Coca ◽  
Eduard Cremades ◽  
Núria Aliaga-Alcalde ◽  
Eliseo Ruiz
Keyword(s):  
Transition Metal ◽  
Magnetic Anisotropy ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Single Molecule Magnets

scholarly journals High-Spin Cobalt(II) Complex with Record-Breaking Anisotropy of the Magnetic Susceptibility According to Paramagnetic NMR Spectroscopy Data

2021 ◽  
Vol 47 (1) ◽  
pp. 10-16
Author(s):  
Ya. A. Pankratova ◽  
Yu. V. Nelyubina ◽  
V. V. Novikov ◽  
A. A. Pavlov
Keyword(s):  
Magnetic Susceptibility ◽  
Nmr Spectroscopy ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Functional Materials ◽  
Medical Diagnostics ◽  
Paramagnetic Nmr ◽  
Single Molecule Magnets

Abstract The tetrahedral cobalt(II) complex [CoL2](HNEt3)2 (I), where L is 1,2-bis(methanesulfonamido)benzene, exhibiting the properties of a single-molecule magnet is synthesized and characterized. The electronic structure parameters of complex I are determined by paramagnetic NMR spectroscopy. They completely reproduce the results of less available methods of studying single-molecule magnets. The value of axial anisotropy of the magnetic susceptibility estimated for complex I (Δχax = 34.5 × 10–32 m3 at 20°C) is record-breaking among all transition metal complexes studied by the NMR method, which provides wide possibilities for the use of complex I as a paramagnetic label for structural biology or as a contrast agent and even a temperature sensor for medical diagnostics. The data obtained indicate the advantages of paramagnetic NMR spectroscopy as a method of investigation of the magnetic properties and electronic structures of highly anisotropic transition metal complexes, which are precursors of many functional materials.

Dalton technical issue “Lanthanide and transition metal complexes as molecular magnets Single-molecule magnets within polyoxometalate-based frameworks

2021 ◽  
Author(s):  
Malihe Babaei Zarch ◽  
Masoud Mirzaei ◽  
Maryam Bazargan ◽  
Sandeep K Gupta ◽  
Franc Meyer ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Molecular Magnets ◽  
Technical Issue ◽  
Hydrothermal Conditions ◽  
Single Molecule Magnets ◽  
Design And Synthesis

As an extension of our interest in polyoxometalates (POMs) and lanthanoids, we report the design and synthesis of two polyoxometalate-based frameworks under hydrothermal conditions; [Ho4(PDA)4(H2O)11][(SiO4)@W12O36]·8H2O (1) and [Tb4(PDA)4(H2O)12][(SiO4)@W12O36]·4H2O (2) (H2PDA...

Measuring giant anisotropy in paramagnetic transition metal complexes with relevance to single-ion magnetism

2016 ◽  
Vol 45 (42) ◽  
pp. 16751-16763 ◽  
Author(s):  
J. Krzystek ◽  
Joshua Telser
Keyword(s):  
Transition Metal ◽  
Magnetic Anisotropy ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Coordination Complexes ◽  
Multiple Methods

“Giant magnetic anisotropy” is a phenomenon identified in certain coordination complexes of nd- and nf-block ions. The strengths and weaknesses of multiple methods used to measure it are evaluated.

α-Pyridinyl Alcohols, α,α’-Pyridine Diols, α-Bipyridinyl Alcohols, and α,α’-Bipyridine Diols as Structure Motifs Towards Important Organic Molecules and Transition Metal Complexes

2020 ◽  
Vol 17 (5) ◽  
pp. 344-366
Author(s):  
Tegene T. Tole ◽  
Johannes H.L. Jordaan ◽  
Hermanus C.M. Vosloo
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Organic Molecules ◽  
Metal Cluster ◽  
Metal Center ◽  
Phosphine Ligands ◽  
High Ability ◽  
Metal Centers

Background: The preparation and use of pyridinyl alcohols as ligands showed incredible increment in the past three decades. Important property of pyridinyl alcoholato ligands is their strong basicity, which is mainly due to the lack of resonance stabilization of the corresponding anion. This strongly basic anionic nature gives them high ability to make bridges between metal centers rather than to bind to only one metal center in a terminal fashion. They are needed as ligands due to their ability to interact with transition metals both covalently (with oxygen) and hemilabile coordination (through nitrogen). Objective: The review focuses on the wide application of α-pyridinyl alcohols, α,α’-pyridine diols, α- bipyridinyl alcohols, and α,α’-bipyridine diols as structure motifs in the preparation of important organic molecules which is due to their strongly basic anionic nature. Conclusion: It is clear from the review that in addition to their synthetic utility in the homogeneous and asymmetric catalytic reactions, the preparation of the crown ethers, cyclic and acyclic ethers, coordinated borates (boronic esters), pyridinyl-phosphine ligands, pyridinyl-phosphite ligands, and pyridinyl-phosphinite ligands is the other broad area of application of pyridinyl alcohols. In addition to the aforementioned applications they are used for modeling mode of action of enzymes and some therapeutic agents. Their strongly basic anionic nature gives them high ability to make bridges between metal centers rather than to bind to only one metal center in a terminal fashion in the synthesis of transition metal cluster complexes. Not least numbers of single molecule magnets that can be used as storage of high density information were the result of transition metal complexes of pyridinyl alcoholato ligands.

scholarly journals Magnetic Anisotropy in “Scorpionate” First-Row Transition-Metal Complexes: A Theoretical Investigation

2015 ◽  
Vol 21 (9) ◽  
pp. 3716-3726 ◽  
Author(s):  
Marko Perić ◽  
Amador García-Fuente ◽  
Matija Zlatar ◽  
Claude Daul ◽  
Stepan Stepanović ◽  
...  
Keyword(s):  
Transition Metal ◽  
Magnetic Anisotropy ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Theoretical Investigation

scholarly journals Spin–Phonon Coupling and Dynamic Zero-Field Splitting Contributions to Spin Conversion Processes in Iron(II) Complexes

2020 ◽  
Author(s):  
Nicholas Higdon ◽  
Alexandra Barth ◽  
Patryk Kozlowski ◽  
Ryan Hadt
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Ligand Field ◽  
Zero Field ◽  
Phonon Coupling ◽  
Zero Field Splitting ◽  
Spin Conversion ◽  
Coupling Terms

Magnetization dynamics of transition metal complexes manifest in properties and phenomena of fundamental and applied interest (e.g., slow magnetic relaxation in single molecule magnets (SMMs), quantum coherence in quantum bits (qubits), and intersystem crossing (ISC) rates in photophysics). While spin–phonon coupling is recognized as an important determinant of these dynamics, additional fundamental studies are required to unravel the nature of the coupling and thus leverage it in molecular engineering approaches. To this end, we describe here a combined ligand field theory and multireference <i>ab initio</i> model to define spin–phonon coupling terms in S = 2 transition metal complexes and demonstrate how couplings originate from both the static and dynamic properties of ground and excited states. By extending concepts to spin conversion processes, ligand field dynamics manifest in the evolution of the excited state origins of zero-field splitting (ZFS) along specific normal mode potential energy surfaces. Dynamic ZFSs provide a powerful means to independently evaluate contributions from spin-allowed and/or -forbidden excited states to spin–phonon coupling terms. Furthermore, ratios between various intramolecular coupling terms for a given mode drive spin conversion processes in transition metal complexes and can be used to analyze mechanisms of ISC. Variations in geometric structure strongly influence the relative intramolecular linear spin–phonon coupling terms and will thus define the overall spin state dynamics. While of general importance for understanding magnetization dynamics, this study links the phenomenon of spin–phonon coupling across fields of single molecule magnetism, quantum materials/qubits, and transition metal photophysics.

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