1. Evidence of Ligand Elasticity Occurring in Temperature-, Light-, and Pressure-Induced Spin Crossover in 1D Coordination Polymers [Fe(3ditz)3]X2 (X = ClO4-, BF4-).
- Author
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Weselski, Marek, Książek, Maria, Kusz, Joachim, Białońska, Agata, Paliwoda, Damian, Hanfland, Michael, Rudolf, Mikołaj F., Ciunik, Zbigniew, and Bronisz, Robert
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LIGANDS (Chemistry) , *ELASTICITY , *POLYMERS , *MOLECULES , *PROPENE , *TEMPERATURE - Abstract
The complexes [M(3ditz)3]X2 [X = ClO4-, M = FeII (1), ZnII (2); X = BF4-, M = FeII (3), ZnII (4); 3ditz = 1,3-di(tetrazol-1-yl)propane] were prepared. Disordering of the propylene chain in 3ditz is not affected by thermally induced spin crossover in 1 (T1/2↓ = 149 K, T1/2↑ = 150 K) and 3 (T1/2↓ = 158, T1/2↑ = 161 K). Low-spin to high-spin (LS→HS) switching triggered by laser-light irradiation (520 nm) also does not influence the disordering of the ligand, leading to restoration of the initial HS phase. Pressurization of crystals results in a reduction of the Fe-N distances by about 0.19 Å, which indicates practically complete spin crossover (SCO). Also, in this case, the disordering of the ligand remains unchanged, although thermally and pressure-induced SCO is accompanied by different changes of 3ditz molecules. Upon thermally induced SCO, perturbation resulting from the reduction of the Fe-N distances is accompanied by a slight elongation of the bridging ligand. In contrast, in the range 0.25-0.55 GPa, the pressure-induced SCO is associated with shrinkage of the 3ditz molecule. Further elevation of pressure results in the inversion of structural changes and - similar to temperature-induced spin crossover - a slight elongation of the ligand molecule takes place. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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