Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Light-Induced Spin State Switching and Relaxation in Spin Pairs of Copper(II)-Nitroxide Based Molecular Magnets. / Tumanov, Sergey V.; Veber, Sergey L.; Tolstikov, Svyatoslav E. и др.
в: Inorganic Chemistry, Том 56, № 19, 02.10.2017, стр. 11729-11737.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Light-Induced Spin State Switching and Relaxation in Spin Pairs of Copper(II)-Nitroxide Based Molecular Magnets
AU - Tumanov, Sergey V.
AU - Veber, Sergey L.
AU - Tolstikov, Svyatoslav E.
AU - Artiukhova, Natalia A.
AU - Romanenko, Galina V.
AU - Ovcharenko, Victor I.
AU - Fedin, Matvey V.
N1 - Publisher Copyright: © 2017 American Chemical Society.
PY - 2017/10/2
Y1 - 2017/10/2
N2 - Similar to spin-crossover (SCO) compounds, spin states of copper(II)-nitroxide based molecular magnets can be switched by various external stimuli including temperature and light. Although photoswitching and reverse relaxation of nitroxide-copper(II)-nitroxide triads were investigated in some detail, similar study for copper(II)-nitroxide spin pairs was still missing. In this work we address photoswitching and relaxation phenomena in exchange-coupled spin pairs of this family of molecular magnets. Using electron paramagnetic resonance (EPR) spectroscopy with photoexcitation, we demonstrate that compared to triad-containing compounds the photoinduced weakly coupled spin (WS) states of copper(II)-nitroxide pairs are remarkably more stable at cryogenic temperatures and relax to the ground strongly coupled spin (SS) states on the scale of days. The structural changes between SS and WS states, e.g., differences in Cu-Onitroxide distances, are much more pronounced for spin pairs than for spin triads in most of the studied copper(II)-nitroxide based molecular magnets. This results in higher energy barrier between WS and SS states of spin pairs and governs higher stability of their photoinduced WS states. Therefore, the longer-lived photoinduced states in copper(II)-nitroxide molecular magnets should be searched within the compounds experiencing largest structural changes upon thermal spin transition. This advancement in understanding of LIESST-like phenomena in copper(II)-nitroxide molecular magnets allows us to propose them as interesting playgrounds for benchmarking the basic factors governing the stability of photoinduced states in other SCO and SCO-like photoswitchable systems.
AB - Similar to spin-crossover (SCO) compounds, spin states of copper(II)-nitroxide based molecular magnets can be switched by various external stimuli including temperature and light. Although photoswitching and reverse relaxation of nitroxide-copper(II)-nitroxide triads were investigated in some detail, similar study for copper(II)-nitroxide spin pairs was still missing. In this work we address photoswitching and relaxation phenomena in exchange-coupled spin pairs of this family of molecular magnets. Using electron paramagnetic resonance (EPR) spectroscopy with photoexcitation, we demonstrate that compared to triad-containing compounds the photoinduced weakly coupled spin (WS) states of copper(II)-nitroxide pairs are remarkably more stable at cryogenic temperatures and relax to the ground strongly coupled spin (SS) states on the scale of days. The structural changes between SS and WS states, e.g., differences in Cu-Onitroxide distances, are much more pronounced for spin pairs than for spin triads in most of the studied copper(II)-nitroxide based molecular magnets. This results in higher energy barrier between WS and SS states of spin pairs and governs higher stability of their photoinduced WS states. Therefore, the longer-lived photoinduced states in copper(II)-nitroxide molecular magnets should be searched within the compounds experiencing largest structural changes upon thermal spin transition. This advancement in understanding of LIESST-like phenomena in copper(II)-nitroxide molecular magnets allows us to propose them as interesting playgrounds for benchmarking the basic factors governing the stability of photoinduced states in other SCO and SCO-like photoswitchable systems.
UR - http://www.scopus.com/inward/record.url?scp=85030551048&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.7b01689
DO - 10.1021/acs.inorgchem.7b01689
M3 - Article
C2 - 28933835
AN - SCOPUS:85030551048
VL - 56
SP - 11729
EP - 11737
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 19
ER -
ID: 9894184