Tuning a Single Ligand System to Stabilize Multiple Spin States of Manganese: A First Example of a Hydrazone-Based Manganese(III) Spin-Crossover Complex

2014 ◽  
Vol 20 (31) ◽  
pp. 9693-9701 ◽  
Author(s):  
Musa S. Shongwe ◽  
Kaltham S. Al-Barhi ◽  
Masahiro Mikuriya ◽  
Harry Adams ◽  
Michael J. Morris ◽  
...  
Keyword(s):  
Spin Crossover ◽  
Spin States ◽  
Ligand System

Interplay between spin crossover and exchange interaction in iron(III) complexes

2009 ◽  
Vol 81 (8) ◽  
pp. 1357-1383 ◽  
Author(s):  
Roman Boča ◽  
Ivan Nemec ◽  
Ivan Šalitroš ◽  
Ján Pavlik ◽  
Radovan Herchel ◽  
...  
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Exchange Interaction ◽  
Spin Crossover ◽  
Magnetic Measurements ◽  
Spin States ◽  
Magnetic Exchange Interaction ◽  
Magnetic Exchange ◽  
Simultaneous Fitting ◽  
Polynuclear Metal Complexes

In the dinuclear and polynuclear metal complexes exhibiting the low-spin (LS) to high-spin (HS) transition, the spin-crossover phenomenon interferes with the magnetic exchange interaction. The latter manifests itself in forming spin-multiplets, which causes a possible overlap of the band originating in different reference spin states (LL, LH, HL, and HH). A series of dinuclear Fe(III) complexes has been prepared; the iron centers are linked by a bidentate bridge (CN-, and diamagnetic metallacyanates {Fe(CN)5(NO)}, {Ni(CN)4}, {Pt(CN)4}, and {Ag(CN)2}). Magnetic measurements confirm that the spin crossover proceeds on the thermal propagation. This information has been completed also by the Mössbauer spectral (MS) data. A theoretical model has been developed that allows a simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, HS mole fraction) on a common set of parameters.

scholarly journals Spin Crossover between the High-Spin and Low-Spin States and Dielectric Switching in the Ionic Crystals of a Fe(II) [2 × 2] Molecular Grid

2020 ◽  
Vol 93 (12) ◽  
pp. 1583-1587
Author(s):  
Yuta Uezu ◽  
Ryo Tsunashima ◽  
Chiaki Tanaka ◽  
Masaru Fujibayashi ◽  
Jun Manabe ◽  
...  
Keyword(s):  
High Spin ◽  
Spin Crossover ◽  
Spin States ◽  
Ionic Crystals

Metal Dilution of Cooperative Spin-Crossover Compounds: When Stable and Metastable High-Spin States Meet

2013 ◽  
Vol 2013 (5-6) ◽  
pp. 968-974 ◽  
Author(s):  
Nicolas Paradis ◽  
Guillaume Chastanet ◽  
François Varret ◽  
Jean-François Létard
Keyword(s):  
High Spin ◽  
Spin Crossover ◽  
Spin States ◽  
High Spin States

scholarly journals Nuclear inelastic scattering and density functional theory studies of a one-dimensional spin crossover [Fe(1,2,4-triazole)2(1,2,4-triazolato)](BF4) molecular chain

2017 ◽  
Vol 19 (29) ◽  
pp. 18880-18889 ◽  
Author(s):  
Kevin Jenni ◽  
Lena Scherthan ◽  
Isabelle Faus ◽  
Jennifer Marx ◽  
Cornelius Strohm ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Inelastic Scattering ◽  
Density Functional ◽  
Spin Crossover ◽  
Nuclear Inelastic Scattering ◽  
Spin States ◽  
Functional Theory ◽  
Vibrational Dynamics ◽  
One Dimensional ◽  
High Spin States

NIS experiments display the vibrational dynamics of the low- and high-spin states of the 1D spin crossover compound [Fe(trzH)2(trz)](BF4) (1).

scholarly journals First-Principles Investigations of Magnetic Anisotropy and Spin-Crossover Behavior of Fe(III)-TBP Complexes

2020 ◽  
Author(s):  
Rishu Khurana ◽  
Sameer Gupta ◽  
Md. Ehesan Ali
Keyword(s):  
Single Molecule ◽  
First Principles ◽  
Density Functional ◽  
Spin Crossover ◽  
Zero Field ◽  
Spin States ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
B3lyp Functional ◽  
D Values

<div>With the ongoing efforts to obtain mononuclear 3d-transition metal complexes that manifest slow relaxation of magnetization and hence, can behave as single molecule magnets (SMMs), we have modelled 14 novel Fe(III) complexes out of which nine behave as potential SMMs. These complexes possess large zero-field splitting (ZFS)</div><div>parameter D in the range of -40 to -60 cm<sup>-1</sup>. The first-principles investigation of the ground-spin state applying density functional theory (DFT) and wave-function based</div><div>multi-configurations methods e.g. SA-CASSCF/NEVPT2 are found to be quite consistent except for few delicate cases with near degenerate spin-states. In such cases, the</div><div>hybrid B3LYP functional is found to be biased towards high-spin (HS) state. Altering the percentage of exact exchange admixed in B3LYP functional leads to intermediate spin</div><div>(IS) ground state consistent with the multireference calculations. The origin of large zero field splitting (ZFS) in the Fe(III)-based trigonal bipyramidal (TBP) complexes</div><div>is investigated and the D-values are further tuned by varying the axial ligands with group XV elements (N, P and As) and equatorial halide ligands from F, Cl, Br and I. Furthermore, a number of complexes are identified with very small Gibbs free energy values indicating the possible spin-crossover phenomenon between the bi-stable spin-states.</div>

scholarly journals Light- and Temperature-Assisted Spin State Annealing: Accessing the Hidden Multistability

2019 ◽  
Author(s):  
Yan-Cong Chen ◽  
Yan Meng ◽  
Jiří Tuček ◽  
Yan-Jie Dong ◽  
Xiao-Wei Song ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Spin State ◽  
Spin Crossover ◽  
Spectral Investigation ◽  
Spin States ◽  
Medium Temperature ◽  
Transition Pathways ◽  
Intelligent Devices ◽  
Thermodynamic Effects ◽  
Temperature Stimulation

Among the responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here in a 2D Hofmann-type coordination polymer [Fe(isoq)<sub>2</sub>{Au(CN)<sub>2</sub>}<sub>2</sub>] (isoq = isoquinoline), hidden multistability of the spin state is accessed by introducing an medium-temperature annealing after a light/temperature stimulation. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified. Such excitation-relaxation and trapping-relaxation joint mechanisms, as ingenious interplays between the kinetic and thermodynamic effects, uncover hidden possibilities for the discovery of multistable materials and the development of multistate intelligent devices.

scholarly journals Low-temperature lifetimes of metastable high-spin states in spin-crossover and in low-spin iron(II) compounds: The rule and exceptions to the rule

2006 ◽  
Vol 250 (13-14) ◽  
pp. 1642-1652 ◽  
Author(s):  
Andreas Hauser ◽  
Cristian Enachescu ◽  
Max Lawson Daku ◽  
Alfredo Vargas ◽  
Nahid Amstutz
Keyword(s):  
Low Temperature ◽  
High Spin ◽  
Spin Crossover ◽  
Spin States ◽  
High Spin States

Isoequilibrium relationships and cooperative effects in spin-state transitions in solution

2008 ◽  
Vol 80 (6) ◽  
pp. 1281-1292 ◽  
Author(s):  
Nader Hassan ◽  
Andrei B. Koudriavtsev ◽  
Wolfgang Linert
Keyword(s):  
Solid State ◽  
High Spin ◽  
Molecular Interactions ◽  
Thermodynamic Model ◽  
Spin Crossover ◽  
Statistical Thermodynamic ◽  
State Transitions ◽  
Spin States ◽  
Cooperative Effects ◽  
High Spin States

Thermal induced spin transitions between low- and high-spin states of Fe(II) complexes are commonly observed in the solid state. Cooperative effects, such as abrupt and two-step spin crossover, are typical for these objects and arise from intermolecular interactions described by several formalisms. These phenomena appear as deviations from the linearity of the respective van't Hoff plots. In solutions, molecular interactions manifest themselves in isoequilibrium relationships (IERs) as well as in a few cases of specific deviations of van't Hoff plots from linearity. The nature of these phenomena will be discussed on the basis of a statistical-thermodynamic model of spin crossover.

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