Anomalous
Pressure Response of Temperature-Induced
Spin Transition and a Pressure-Induced Spin Transition in Two-Dimensional
Hofmann Coordination Polymers
posted on 2023-12-30, 14:09authored byRuixin Li, Georgiy Levchenko, Carlos Bartual-Murgui, Hennagii Fylymonov, Wei Xu, Zhaodong Liu, Quanjun Li, Bingbing Liu, Jose Antonio Real
Spin
transition (ST) compounds have been extensively studied because
of the changes in rich physicochemical properties accompanying the
ST process. The study of ST mainly focuses on the temperature-induced
spin transition (TIST). To further understand the ST, we explore the
pressure response behavior of TIST and pressure-induced spin transition
(PIST) of the 2D Hofmann-type ST compounds [Fe(Isoq)2M(CN)4] (Isoq-M) (M = Pt, Pd, Isoq = isoquinoline).
The TISTs of both Isoq-Pt and Isoq-Pd compounds
exhibit anomalous pressure response, where the transition temperature
(T1/2) exhibits a nonlinear pressure dependence
and the hysteresis width (ΔT1/2)
exhibits a nonmonotonic behavior with pressure, by the synergistic
influence of the intermolecular interaction and the distortion of
the octahedral coordination environment. And the distortion of the
octahedra under critical pressures may be the common behavior of 2D
Hofmann-type ST compounds. Moreover, ΔT1/2 is increased compared with that before compression because
of the partial irreversibility of structural distortion after decompression.
At room temperature, both compounds exhibit completely reversible
PIST. Because of the greater change in mechanical properties before
and after ST, Isoq-Pt exhibits a more abrupt ST than Isoq-Pd. In addition, it is found that the hydrostatic properties
of the pressure transfer medium (PTM) significantly affect the PIST
due to their influence on spin-domain formation.