Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Intermolecular Spin-Crossover-like Phenomenon Sensitive to Applied External Pressure in Heterospin Crystals. / Maryunina, Kseniya; Yamaguchi, Koyo; Nishihara, Sadafumi и др.
в: Crystal Growth and Design, Том 20, № 4, 01.04.2020, стр. 2796-2802.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Intermolecular Spin-Crossover-like Phenomenon Sensitive to Applied External Pressure in Heterospin Crystals
AU - Maryunina, Kseniya
AU - Yamaguchi, Koyo
AU - Nishihara, Sadafumi
AU - Inoue, Katsuya
AU - Letyagin, Gleb
AU - Romanenko, Galina
AU - Barskaya, Irina
AU - Veber, Sergey
AU - Fedin, Matvey
AU - Bogomyakov, Artem
AU - Petrova, Marina
AU - Morozov, Vitaly
AU - Ovcharenko, Victor
N1 - Publisher Copyright: Copyright © 2020 American Chemical Society. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/4/1
Y1 - 2020/4/1
N2 - The interaction of Cu(acF6)2 with the stable imino nitroxide 2-(pyridin-3-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl (ImN-mPy) at a ratio of 2:1 led to the formation of a new complex [{Cu(acF6)2}2(ImN-mPy)], which can exist in two polymorphic modifications, 1 and 2. The solid phases of both polymorphs are formed by binuclear molecules, in which the paramagnetic ligand performs the ditopic function due to the coordination of the imine N atoms of the imidazoline and pyridine heterocycles; the >N-·O fragment is not involved in coordination. The intramolecular exchange interactions in the {Cu2+-N=C-N-·O} exchange clusters were found to be ferromagnetic (JCu-R > +100 cm-1). When the cooling-heating cycles are repeated, the χT(T) dependence for 2 acquires a hysteresis with T = 37 K and T = 46 K due to the appearance of a strong antiferromagnetic intermolecular exchange between the >N-·O fragments of adjacent molecules. It was impossible to trace the structural changes in the solid compound at T < 50 K because the crystals cracked and lost their quality during the phase transitions. Coating the crystals with epoxide resin prevented their decomposition, but completely suppressed the spin transition. Immersion of the polymorph 2 crystals in a pressure-transmitting medium Daphne7373, which froze together with the crystals of the experimental sample at T < 200 K, also suppressed the transition to the low-spin state. An increase in the external pressure to 1.8 kbar led to stabilization of the strongly coupled low-spin state in the {>N-·O···O·-N <} intermolecular exchange clusters already at room temperature.
AB - The interaction of Cu(acF6)2 with the stable imino nitroxide 2-(pyridin-3-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl (ImN-mPy) at a ratio of 2:1 led to the formation of a new complex [{Cu(acF6)2}2(ImN-mPy)], which can exist in two polymorphic modifications, 1 and 2. The solid phases of both polymorphs are formed by binuclear molecules, in which the paramagnetic ligand performs the ditopic function due to the coordination of the imine N atoms of the imidazoline and pyridine heterocycles; the >N-·O fragment is not involved in coordination. The intramolecular exchange interactions in the {Cu2+-N=C-N-·O} exchange clusters were found to be ferromagnetic (JCu-R > +100 cm-1). When the cooling-heating cycles are repeated, the χT(T) dependence for 2 acquires a hysteresis with T = 37 K and T = 46 K due to the appearance of a strong antiferromagnetic intermolecular exchange between the >N-·O fragments of adjacent molecules. It was impossible to trace the structural changes in the solid compound at T < 50 K because the crystals cracked and lost their quality during the phase transitions. Coating the crystals with epoxide resin prevented their decomposition, but completely suppressed the spin transition. Immersion of the polymorph 2 crystals in a pressure-transmitting medium Daphne7373, which froze together with the crystals of the experimental sample at T < 200 K, also suppressed the transition to the low-spin state. An increase in the external pressure to 1.8 kbar led to stabilization of the strongly coupled low-spin state in the {>N-·O···O·-N <} intermolecular exchange clusters already at room temperature.
KW - NITRONYL NITROXIDE RADICALS
KW - MAGNETIC-PROPERTIES
KW - COPPER(II) COMPLEXES
KW - COORDINATION-COMPOUNDS
KW - IMINO
KW - TRANSITION
KW - CU(HFAC)(2)
KW - DEPENDENCE
KW - CHAINS
UR - http://www.scopus.com/inward/record.url?scp=85083740575&partnerID=8YFLogxK
U2 - 10.1021/acs.cgd.0c00240
DO - 10.1021/acs.cgd.0c00240
M3 - Article
AN - SCOPUS:85083740575
VL - 20
SP - 2796
EP - 2802
JO - Crystal Growth and Design
JF - Crystal Growth and Design
SN - 1528-7483
IS - 4
ER -
ID: 24094043