Unique spin transition and wide thermal hysteresis loop for a cobalt(ii) compound with long alkyl chain

2011 ◽  
Vol 40 (10) ◽  
pp. 2167-2169 ◽  
Author(s):  
Shinya Hayami ◽  
Kazuya Kato ◽  
Yasuka Komatsu ◽  
Akira Fuyuhiro ◽  
Masaaki Ohba
Keyword(s):  
Hysteresis Loop ◽  
Alkyl Chain ◽  
Thermal Hysteresis ◽  
Spin Transition ◽  
Thermal Hysteresis Loop ◽  
Unique Spin ◽  
Long Alkyl Chain

Dynamical control of the spin transition inside the thermal hysteresis loop of a spin-crossover single crystal

2016 ◽  
Vol 486 ◽  
pp. 187-191 ◽  
Author(s):  
Kamel Boukheddaden ◽  
Mouhamadou Sy ◽  
Miguel Paez-Espejo ◽  
Ahmed Slimani ◽  
François Varret
Keyword(s):  
Single Crystal ◽  
Hysteresis Loop ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Spin Transition ◽  
Thermal Hysteresis Loop ◽  
Dynamical Control

Study of switching in spin transition compounds within the mechanoelastic model with realistic parameters

2016 ◽  
Vol 18 (30) ◽  
pp. 20591-20599 ◽  
Author(s):  
Cristian Enachescu ◽  
Andreas Hauser
Keyword(s):  
Monte Carlo ◽  
Hysteresis Loop ◽  
Spin State ◽  
Thermal Hysteresis ◽  
Spin Transition ◽  
Metropolis Method ◽  
Thermal Hysteresis Loop

Thermal hysteresis loop calculated using the Monte Carlo Metropolis method and snapshots of the system just before percolation, showing clusters of the same spin state molecules near corners. Variation of the compression of the connecting spring while a molecule i flips from the LS to the HS state.

Magnetic, Spectral and Structural Aspects of Spin Transitions in Iron(II) Complexes of 2-(Pyrazol-3-yl)pyridine and 3-(Thiazol-2-yl)pyrazole

1999 ◽  
Vol 52 (2) ◽  
pp. 109 ◽  
Author(s):  
Lucia S. Harimanow ◽  
Kristian H. Sugiyarto ◽  
Donald C. Craig ◽  
Marcia L. Scudder ◽  
Harold A. Goodwin
Keyword(s):  
Hydrogen Bonding ◽  
Hysteresis Loop ◽  
Room Temperature ◽  
Thermal Hysteresis ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Thermal Hysteresis Loop ◽  
Lower Temperature ◽  
Structural Aspects

Tris(ligand)iron(II) complexes of 2-(pyrazol-3-yl)pyridine (3ppH) and 3-(thiazol-2-yl)pyrazole (3tpH) undergo temperature-induced singlet (1A1) ⇔ quintet (5T2) transitions. The transition in [Fe(3ppH)3] [CF3SO3]2.2H2O is continuous and centred above room temperature while that in the anhydrous triflate salt is discontinuous and is centred below room temperature. The latter transition occurs via a thermal hysteresis loop of width 12 K, Tc↓ and Tc↑ being 229 and 241 K, respectively. The displacement of the transition to lower temperature in the anhydrous salt is believed to be associated with the loss of hydrogen bonding involving the uncoordinated pyrazole >NH group and solvate water. In [Fe(3tpH)2(3tp)] [ClO4].2H2O and [Fe(3tpH)2(3tp)] [BF4].2H2O (3tp is the deprotonated ligand) continuous transitions are observed, centred below room temperature. In these instances the displacement is consistent with the intrinsically weaker field of the bidentate system containing two five-membered heterocycles. Structural data were obtained for [Fe(3ppH)3][CF3SO3]2.2H2O, [Fe(3tpH)3] [BF4]2.1·5H2O and [Ni(3tpH)3] [BF4]2.2(3tpH). The average metal–nitrogen distances in the complexes are 1·97, 2·18 and 2·09 Å, severally. The large difference in the distances for the two iron complexes arises from the different ground states: a singlet for the 3ppH complex and a quintet for the 3tpH complex. In all three salts there is extensive hydrogen bonding involving the pyrazole >NH groups, the anions and the solvate molecules. [Fe(3ppH)3] [CF3SO3]2.2H2O: monoclinic, space group P21/c, a 12·33(1), b 24·44(1), c 12·55(1) Å, β 115·27(4)°, Z 4. [Fe(3tpH)3] [BF4]2.1·5H2O: monoclinic, space group C 2/c, a 41·56(2), b 16·418(3), c 18·154(7) Å, β 106·94(2)°, Z 8. [Ni(3tpH)3] [BF4]2.2(3tpH):P bcn, a 14·928(2), b 15·310 (3), c 17·882 (3) Å, Z 4.

Compensation effects and relation between the activation energy of spin transition and the hysteresis loop width for an iron(ii) complex

2016 ◽  
Vol 18 (25) ◽  
pp. 16690-16699 ◽  
Author(s):  
Mark B. Bushuev ◽  
Denis P. Pishchur ◽  
Elena B. Nikolaenkova ◽  
Viktor P. Krivopalov
Keyword(s):  
Hysteresis Loop ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Activation Barrier ◽  
Spin Transition ◽  
Hysteresis Loops ◽  
High Activation ◽  
Activation Barriers ◽  
Spin Crossover Complexes ◽  
Hysteresis Loop Width

Wide thermal hysteresis loops for iron(ii) spin crossover complexes are associated with high activation barriers: the higher the activation barrier, the wider the hysteresis loop for a series of related spin crossover systems.

Bidirectional photo-switching of the spin state of iron(II) ions in a triazol based spin crossover complex within the thermal hysteresis loop

2009 ◽  
Vol 477 (1-3) ◽  
pp. 156-159 ◽  
Author(s):  
Nawel Ould Moussa ◽  
Denis Ostrovskii ◽  
Victor Martinez Garcia ◽  
Gábor Molnár ◽  
Koichiro Tanaka ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Spin State ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Thermal Hysteresis Loop

A Surprisingly Large Thermal Hysteresis Loop in a Reversible Phase Transition of RbxMn [Fe(CN)6](x+2)/3×zH2O.

ChemInform ◽  
2005 ◽  
Vol 36 (14) ◽  
pp. no-no
Author(s):  
Shin-ichi Ohkoshi ◽  
Tomoyuki Matsuda ◽  
Hiroko Tokoro ◽  
Kazuhito Hashimoto
Keyword(s):  
Phase Transition ◽  
Hysteresis Loop ◽  
Thermal Hysteresis ◽  
Reversible Phase Transition ◽  
Thermal Hysteresis Loop ◽  
Reversible Phase

scholarly journals Hysteretic Thermal Spin-Crossover and Symmetry Breaking in Heteroleptic Fe(II) Complexes Using Alkyl Chain Substituted 2,2’-Dipyridylamine Ligands

2019 ◽  
Author(s):  
Blaise Geoghegan ◽  
Wasinee Phonsri ◽  
Peter Horton ◽  
James Orton ◽  
Simon Coles ◽  
...  
Keyword(s):  
Phase Transition ◽  
Spin Crossover ◽  
Alkyl Chain ◽  
Thermal Hysteresis ◽  
Variable Temperature ◽  
Spin Transition ◽  
Magnetic Data ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Bond Lengths

The alkyl chain carrying ligands N,N-di(pyridin-2-yl)butanamide (LC4) and N,N-di(pyridin-2-yl)decanamide (LC10) were combined with NCS- co-ligands to form the neutral heteroleptic Fe(II) complexes trans-[FeII(LC4)2(NCS)2] (1C4) and trans [FeII(LC10)2(NCS)2] (1C10). Variable temperature crystallographic studies revealed that 1C4 is in the orthorhombic space group Pna21 between 85-200 K whereas 1C10 is in the monoclinic space group P21/c between 85-105 K before undergoing a crystallographic phase transition to the triclinic space group P1􀴤 by 140 K. The average Fe-N bond lengths suggest that at 85 K 1C4 contains LS Fe(II) centres; However, the ca. 0.18 Å increase in the average Fe-N bond lengths between 85 and 120 K suggests a spin-transition occurs within this temperature interval and the HS state is predominant beyond this. 1C10 contains LS Fe(II) centres between 85 and 105 K. Upon warming from 105 to 140 K the average Fe-N bond lengths increase by ca. 0.19 Å, which suggests that a spin-transition to the HS accompanies the P21/c to P1􀴤 crystallographic phase transition. Solid-state magnetic susceptibility measurements showed that 1C4 undergoes semi-abrupt spin-crossover with T1/2 = 127.5 K and a thermal hysteresis of ca. 13 K whereas, 1C10 undergoes an abrupt spin-crossover with T1/2 = 119.0 K, and is also accompanied by thermal hysteresis of ca. 4 K. The crystallographic and magnetic data show that the length of the complex’s alkyl chain substituents can have a large impact on the structure of the crystal lattice as well as a subtle effect on the T1/2 value for thermal spin-crossover.

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