Dual-supramolecular contacts induce extreme Hofmann framework distortion and multi-stepped spin-crossover

2021 ◽  
Vol 50 (4) ◽  
pp. 1434-1442
Author(s):  
Manan Ahmed ◽  
Helen E. A. Brand ◽  
Vanessa K. Peterson ◽  
Jack K. Clegg ◽  
Cameron J. Kepert ◽  
...  
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
Supramolecular Contacts ◽  
Transition Behaviour ◽  
Crossover Transition

A ligand with dual-supramolecular contact character has been exploited to induce extreme Hofmann framework distortion and a resultant multi-stepped spin-crossover transition behaviour with a mismatch between structural and spin-state periodicity.

scholarly journals Four-step iron(ii) spin state cascade driven by antagonistic solid state interactions

2017 ◽  
Vol 8 (1) ◽  
pp. 701-707 ◽  
Author(s):  
Natasha F. Sciortino ◽  
Katrina A. Zenere ◽  
Maggie E. Corrigan ◽  
Gregory J. Halder ◽  
Guillaume Chastanet ◽  
...  
Keyword(s):  
Solid State ◽  
Spin State ◽  
Spin Crossover ◽  
Type Material ◽  
Two Dimensional ◽  
Crossover Transition

A rare four-step spin crossover transition has been attained in a two-dimensional Hofmann-type material through the presence of an array of antagonistic host–host and host–guest interactions.

scholarly journals Magnetic Field Perturbations to a Soft X-Ray Activated Fe (II) Molecular Spin State Transition

2021 ◽  
Author(s):  
Guanhua Hao ◽  
Alpha T. N'Diaye ◽  
Thilini K. Ekanayaka ◽  
Ashley S. Dale ◽  
Xuanyuan Jiang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin State ◽  
Spin Crossover ◽  
State Transition ◽  
Spin Moment ◽  
X Ray ◽  
Spin State Transition ◽  
Free Case ◽  
Increasing Temperature ◽  
Crossover Transition

The X-ray induced spin crossover transition of an Fe(II) molecular thin film in the presence and absence of a magnetic field has been investigated. The thermal activation energy barrier in the soft X-ray activation of the spin crossover transition for [Fe{H2B(pz)2}2(bipy)] molecular thin films is reduced in the presence of an applied magnetic field, as measured through X-ray absorption spectroscopy at various temperatures. The influence of a 1.8 T magnetic field is sufficient to cause deviations from the expected exponential spin state transition behavior that is measured in the field free case. We find that orbital moment diminishes with increasing temperature, relative to the spin moment in the vicinity of room temperature.

scholarly journals Magnetic Field Perturbations to a Soft X-ray-Activated Fe (II) Molecular Spin State Transition

2021 ◽  
Vol 7 (10) ◽  
pp. 135
Author(s):  
Guanhua Hao ◽  
Alpha T. N’Diaye ◽  
Thilini K. Ekanayaka ◽  
Ashley S. Dale ◽  
Xuanyuan Jiang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin State ◽  
Spin Crossover ◽  
State Transition ◽  
Spin Moment ◽  
X Ray ◽  
Spin State Transition ◽  
Free Case ◽  
Increasing Temperature ◽  
Crossover Transition

The X-ray-induced spin crossover transition of an Fe (II) molecular thin film in the presence and absence of a magnetic field has been investigated. The thermal activation energy barrier in the soft X-ray activation of the spin crossover transition for [Fe{H2B(pz)2}2(bipy)] molecular thin films is reduced in the presence of an applied magnetic field, as measured through X-ray absorption spectroscopy at various temperatures. The influence of a 1.8 T magnetic field is sufficient to cause deviations from the expected exponential spin state transition behavior which is measured in the field free case. We find that orbital moment diminishes with increasing temperature, relative to the spin moment in the vicinity of room temperature.

Influence of ligand substituent conformation on the spin state of an iron(ii)/di(pyrazol-1-yl)pyridine complex

2021 ◽  
Vol 50 (10) ◽  
pp. 3464-3467
Author(s):  
Rafal Kulmaczewski ◽  
Mark J. Howard ◽  
Malcolm A. Halcrow
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
Solution Phase ◽  
Pyridine Complex

The temperature of the solution-phase spin-crossover equilibrium in iron(ii) complexes of 4-alkylsulfanyl-2,6-di{pyrazol-1-yl}pyridine (bppSR) complexes depends strongly on the alkylsulfanyl substituent.

scholarly journals Spin-state-dependent electrical conductivity in single-walled carbon nanotubes encapsulating spin-crossover molecules

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Julia Villalva ◽  
Aysegul Develioglu ◽  
Nicolas Montenegro-Pohlhammer ◽  
Rocío Sánchez-de-Armas ◽  
Arturo Gamonal ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Spin State ◽  
Spin Crossover ◽  
Single Walled Carbon Nanotubes ◽  
Guest Molecules ◽  
Spintronic Devices ◽  
Single Walled Carbon ◽  
State Dependent ◽  
Lack Of Control ◽  
Walled Carbon Nanotubes

AbstractSpin crossover (SCO) molecules are promising nanoscale magnetic switches due to their ability to modify their spin state under several stimuli. However, SCO systems face several bottlenecks when downscaling into nanoscale spintronic devices: their instability at the nanoscale, their insulating character and the lack of control when positioning nanocrystals in nanodevices. Here we show the encapsulation of robust Fe-based SCO molecules within the 1D cavities of single-walled carbon nanotubes (SWCNT). We find that the SCO mechanism endures encapsulation and positioning of individual heterostructures in nanoscale transistors. The SCO switch in the guest molecules triggers a large conductance bistability through the host SWCNT. Moreover, the SCO transition shifts to higher temperatures and displays hysteresis cycles, and thus memory effect, not present in crystalline samples. Our results demonstrate how encapsulation in SWCNTs provides the backbone for the readout and positioning of SCO molecules into nanodevices, and can also help to tune their magnetic properties at the nanoscale.

scholarly journals Spin Crossover in Nickel(II) Tetraphenylporphyrinate via Forced Axial Coordination at the Air/Water Interface

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4155
Author(s):  
Alexander V. Shokurov ◽  
Daria S. Kutsybala ◽  
Andrey P. Kroitor ◽  
Alexander A. Dmitrienko ◽  
Alexander G. Martynov ◽  
...  
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
High Spin State ◽  
Water Interface ◽  
Metal Centers ◽  
Axial Coordination ◽  
Vis Spectroscopy ◽  
Air Water Interface ◽  
Nickel Cation

Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)2, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer.

scholarly journals Programmable spin-state switching in a mixed-valence spin-crossover iron grid

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Takuto Matsumoto ◽  
Graham N. Newton ◽  
Takuya Shiga ◽  
Shinya Hayami ◽  
Yuta Matsui ◽  
...  
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
Mixed Valence ◽  
State Switching

Spin-State Ordering on One Sub-lattice of a Mononuclear Iron(III) Spin Crossover Complex Exhibiting LIESST and TIESST

2014 ◽  
Vol 20 (19) ◽  
pp. 5613-5618 ◽  
Author(s):  
Kevin D. Murnaghan ◽  
Chiara Carbonera ◽  
Loic Toupet ◽  
Michael Griffin ◽  
Marinela M. Dîrtu ◽  
...  
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
Mononuclear Iron

scholarly journals Stabilization of the Low-Spin State in a Mononuclear Iron(II) Complex and High-Temperature Cooperative Spin Crossover Mediated by Hydrogen Bonding

2015 ◽  
Vol 22 (1) ◽  
pp. 331-339 ◽  
Author(s):  
Sipeng Zheng ◽  
Niels R. M. Reintjens ◽  
Maxime A. Siegler ◽  
Olivier Roubeau ◽  
Elisabeth Bouwman ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
High Temperature ◽  
Spin State ◽  
Spin Crossover ◽  
Mononuclear Iron

scholarly journals Structural movies of the gradual spin-crossover in a molecular complex at various physical scales

2016 ◽  
Vol 18 (40) ◽  
pp. 28307-28315 ◽  
Author(s):  
S. Lakhloufi ◽  
M. H. Lemée-Cailleau ◽  
G. Chastanet ◽  
P. Rosa ◽  
N. Daro ◽  
...  
Keyword(s):  
Spin State ◽  
Molecular Complex ◽  
Spin Crossover ◽  
Structural Determination ◽  
Thermally Induced ◽  
Mononuclear Iron

The thermally induced Spin-CrossOver (SCO) undergone by the mononuclear iron(ii) complex [Fe(PM-AzA)2(NCS)2] (PM = N-2′-pyridylmethylene, AzA = 4-(phenylazo)aniline) is fully pictured by a quasi-continuous structural determination all along the spin-state modification within the sample.

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