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

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.

2016 ◽  
Vol 486 ◽  
pp. 187-191 ◽  
Author(s):  
Kamel Boukheddaden ◽  
Mouhamadou Sy ◽  
Miguel Paez-Espejo ◽  
Ahmed Slimani ◽  
François Varret

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

2011 ◽  
Vol 40 (10) ◽  
pp. 2167-2169 ◽  
Author(s):  
Shinya Hayami ◽  
Kazuya Kato ◽  
Yasuka Komatsu ◽  
Akira Fuyuhiro ◽  
Masaaki Ohba

Polyhedron ◽  
2003 ◽  
Vol 22 (14-17) ◽  
pp. 2453-2456 ◽  
Author(s):  
Jorge Linares ◽  
Cristian Enachescu ◽  
Kamel Boukheddaden ◽  
François Varret

1999 ◽  
Vol 52 (2) ◽  
pp. 109 ◽  
Author(s):  
Lucia S. Harimanow ◽  
Kristian H. Sugiyarto ◽  
Donald C. Craig ◽  
Marcia L. Scudder ◽  
Harold A. Goodwin

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.


2016 ◽  
Vol 18 (25) ◽  
pp. 16690-16699 ◽  
Author(s):  
Mark B. Bushuev ◽  
Denis P. Pishchur ◽  
Elena B. Nikolaenkova ◽  
Viktor P. Krivopalov

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.


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