Reaction of the unidentate pyridine ligand containing a bulky t-butyl substituent with Fe2+ and [Au(CN)2]− affords a new type of spin crossover (SCO) coordination polymer in the 1D compound [Fe(4-tBupy)3][Au(CN)2]2⋅0.5H2O (1), which is formed by chains of Fe(II) complexes linked through bridging [Au(CN)2]− with three terminal 4-tBupy and one monodentate [Au(CN)2]− ligands completing the octahedral coordination around Fe(II). Longer reaction times led to the minor products [Fe(4-tBupy)2][Au(CN)2]2 (2), which presents a 2D structure more similar to that found in the other SCO compounds based on [Au(CN)2]−, and the 1D compound [Fe(4-tBupy)2(MeOH)][Au(CN)2]2 (3), in which one of the three terminal 4-tBupy found in 1 is replaced by a coordinating MeOH molecule. Magnetic measurements of 1 show an abrupt spin transition with the temperature with hysteresis and light-induced excited spin-state trapping effect. Structural analysis of 2 and 3 indicates that Fe(II) remains in the high-spin state in these compounds.
Thermal- and photo-induced spin crossover in the 1D coordination polymer [Fe(4-tBupy)3][Au(CN)2]2 (4-tBupy = 4-tert-butylpyridine)
Note: This paper is part of the Special Topic on Spin Transition Materials: Molecular and Solid-State.
Víctor García-López, Miguel Clemente-León, Eugenio Coronado; Thermal- and photo-induced spin crossover in the 1D coordination polymer [Fe(4-tBupy)3][Au(CN)2]2 (4-tBupy = 4-tert-butylpyridine). J. Appl. Phys. 28 March 2021; 129 (12): 123903. https://doi.org/10.1063/5.0046998
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