TY - JOUR
T1 - Magnetic relaxation behavior of a spatially closed dysprosium(III) phthalocyaninato double-decker complex
AU - Katoh, Keiichi
AU - Umetsu, Kaori
AU - Breedlove Brian, K.
AU - Yamashita, Masahiro
N1 - Funding Information:
This work was financially supported by a Grant-in-Aid for Scientific Research(s) (20225003) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan.
PY - 2012/6
Y1 - 2012/6
N2 - The SMM properties of the spatially closed Dy(III) double-decker Pc complex Dy(obPc) 2 (1), which is equivalent to a pseudo dinuclear complex, are reported. Complex 1 crystallized with ethanol in the crystal lattice in the monoclinic space group P2 1/n and was isomorphous with Tb(obPc) 2 (3), which is arranged in a dimer structure along the b axis. The intermetallic Dy-Dy distance was determined to be 0.756 nm. χ M T versus T plots for 1 decreased with a decrease in T, which suggests the existence of an antiferromagnetic (AF) interaction between the Dy 3+ ions. The M-H curve for 1 at 1.8 K showed magnetic hysteresis. In ac susceptibility measurements on a powder sample of 1, which were dependent on the applied ac field, indicating that 1 is an single molecule magnet (SMM), a maximum appeared at 22 K at an ac frequency (f) of 1488 Hz. The shape of the peaks drastically changed, and the peaks did not shift when an H dc large enough to suppress the quantum tunneling of the magnetization (QTM) was applied. The energy barrier (Δ/hc) was estimated to be 44 cm -1 with a pre-exponential factor (τ 0) of 1.6 × 10 -5 s from an Arrhenius plot. Our results suggest that the SMM/magnetic properties of 1 significantly change in a dc magnetic field. These relaxation mechanisms are related to the energy gap of the ground state and to QTM.
AB - The SMM properties of the spatially closed Dy(III) double-decker Pc complex Dy(obPc) 2 (1), which is equivalent to a pseudo dinuclear complex, are reported. Complex 1 crystallized with ethanol in the crystal lattice in the monoclinic space group P2 1/n and was isomorphous with Tb(obPc) 2 (3), which is arranged in a dimer structure along the b axis. The intermetallic Dy-Dy distance was determined to be 0.756 nm. χ M T versus T plots for 1 decreased with a decrease in T, which suggests the existence of an antiferromagnetic (AF) interaction between the Dy 3+ ions. The M-H curve for 1 at 1.8 K showed magnetic hysteresis. In ac susceptibility measurements on a powder sample of 1, which were dependent on the applied ac field, indicating that 1 is an single molecule magnet (SMM), a maximum appeared at 22 K at an ac frequency (f) of 1488 Hz. The shape of the peaks drastically changed, and the peaks did not shift when an H dc large enough to suppress the quantum tunneling of the magnetization (QTM) was applied. The energy barrier (Δ/hc) was estimated to be 44 cm -1 with a pre-exponential factor (τ 0) of 1.6 × 10 -5 s from an Arrhenius plot. Our results suggest that the SMM/magnetic properties of 1 significantly change in a dc magnetic field. These relaxation mechanisms are related to the energy gap of the ground state and to QTM.
KW - double-decker complex
KW - dysprosium
KW - magnetic relaxation process
KW - pseudo dinuclear complex
KW - single-molecule magnets
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U2 - 10.1007/s11426-012-4615-9
DO - 10.1007/s11426-012-4615-9
M3 - Article
AN - SCOPUS:84862524138
SN - 1674-7291
VL - 55
SP - 918
EP - 925
JO - Science China Chemistry
JF - Science China Chemistry
IS - 6
ER -