TY - JOUR
T1 - Field-induced slow magnetic relaxation of monoand dinuclear dysprosium(III) complexes coordinated by a chloranilate with different resonance forms
AU - Ishikawa, Ryuta
AU - Michiwaki, Shoichi
AU - Noda, Takeshi
AU - Katoh, Keiichi
AU - Yamashita, Masahiro
AU - Matsubara, Kouki
AU - Kawata, Satoshi
N1 - Publisher Copyright:
© 2018 by the authors.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - We synthesized the dinuclear and mononuclear dysprosium(III) complexes [{Dy(Tp)2}2(Cl2An)]˙ 2CH2Cl2 (1) and [Co(Cp)2][Dy(Tp)2(Cl2An)] (3), where Cl2An2- and Tp- are the chloranilate and hydrotris(pyrazolyl)borate ligand, respectively. In addition, the magnitude of the magnetic coupling between the lanthanide centers through the Cl2An2- bridge has been probed through the synthesis of [{Gd(Tp)2}2(Cl2An)]˙ 2CH2Cl22 (2), which is a gadolinium(III) analogue of 1. Complexes 1-3 were characterized by infrared (IR) spectroscopy, elemental analysis, single-crystal X-ray diffraction, and SQUID measurements. IR and single-crystal X-ray structural analyses confirm that the coordination environments of the lanthanide(III) centers in 1 and 3 are similar to each other; i.e., eight-coordinated metal centers, each occupied by an N6O2 donor set from two Tp- ligands and one Cl2An2- ligand. The coordination geometries of the lanthanide(III) centers in 1 and 2 are distorted triangular dodecahedral, while that in the mononuclear complex 3 is square antiprismatic, where the Cl2An2- ligand takes the bi-separated delocalized form in 1 and 2, and the o-quinone form in 3. Alternating-current (AC) magnetic studies clearly reveal that both 1 and 3 exhibit field-induced slow relaxations of magnetization that occur via Raman and direct processes. Complexes 1 and 3 exhibit different spin relaxation behavior, which reflects the coordination geometry around each DyIII center and its nuclearity, as well as the molecular packing in the crystal lattice. Although the magnetic analysis of 2 revealed negligible magnetic coupling, Cl2An2- bridges with small biases may form in the dinuclear complexes, which play roles in the spin relaxation dynamics through dipolar interactions.
AB - We synthesized the dinuclear and mononuclear dysprosium(III) complexes [{Dy(Tp)2}2(Cl2An)]˙ 2CH2Cl2 (1) and [Co(Cp)2][Dy(Tp)2(Cl2An)] (3), where Cl2An2- and Tp- are the chloranilate and hydrotris(pyrazolyl)borate ligand, respectively. In addition, the magnitude of the magnetic coupling between the lanthanide centers through the Cl2An2- bridge has been probed through the synthesis of [{Gd(Tp)2}2(Cl2An)]˙ 2CH2Cl22 (2), which is a gadolinium(III) analogue of 1. Complexes 1-3 were characterized by infrared (IR) spectroscopy, elemental analysis, single-crystal X-ray diffraction, and SQUID measurements. IR and single-crystal X-ray structural analyses confirm that the coordination environments of the lanthanide(III) centers in 1 and 3 are similar to each other; i.e., eight-coordinated metal centers, each occupied by an N6O2 donor set from two Tp- ligands and one Cl2An2- ligand. The coordination geometries of the lanthanide(III) centers in 1 and 2 are distorted triangular dodecahedral, while that in the mononuclear complex 3 is square antiprismatic, where the Cl2An2- ligand takes the bi-separated delocalized form in 1 and 2, and the o-quinone form in 3. Alternating-current (AC) magnetic studies clearly reveal that both 1 and 3 exhibit field-induced slow relaxations of magnetization that occur via Raman and direct processes. Complexes 1 and 3 exhibit different spin relaxation behavior, which reflects the coordination geometry around each DyIII center and its nuclearity, as well as the molecular packing in the crystal lattice. Although the magnetic analysis of 2 revealed negligible magnetic coupling, Cl2An2- bridges with small biases may form in the dinuclear complexes, which play roles in the spin relaxation dynamics through dipolar interactions.
KW - Lanthanide ions
KW - Single-ion magnets
KW - Single-molecule magnets
KW - Slow magnetic relaxation
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U2 - 10.3390/inorganics6010007
DO - 10.3390/inorganics6010007
M3 - Article
AN - SCOPUS:85045349360
VL - 6
JO - Inorganics
JF - Inorganics
SN - 2304-6740
IS - 1
M1 - 7
ER -