Tohoku University · 재료과학
요지 호리 교수의 연구실은 주로 랜타니드 이온을 중심으로 한 단일분자자석(SMM)의 설계 및 물성 연구를 핵심으로 하며, 특히 희토류 이온 간의 f-f 상호작용이 SMM 성능에 미치는 영향을 고해상도 구조 분석과 정밀한 자화 측정을 통해 규명하고자 합니다. 다층 구조를 가진 페타코발탄산 복합체(이중, 삼중, 다중 디커)를 합성하여 이온 간 거리와 대칭성의 변화가 자기 이완 메커니즘에 어떻게 영향을 주는지 체계적으로 연구하고 있습니다. 또한 초분자적 상호작용을 활용한 고분자 매트릭스 내에서의 SMM 성능 향상 전략도 탐구하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Single-molecule magnet (SMM) properties of terbium(III)-phthalocyaninato quintuple-decker complex TbCdCdTb were studied and were compared with those of other multiple-decker complexes (triple-decker: TbTb, quadruple-decker: TbCdTb) to elucidate the relationship between magnetic dipole interactions and SMM properties. From X-ray crystallography performed with synchrotron radiation, the Tb(III)-Tb(III) distance in TbCdCdTb was determined to be 9.883 Å. From alternating current magnetic studies on
A Tb<sup>III</sup> -phthalocyaninato double-decker ([1]<sup>0</sup> ) single-molecule magnet (SMM) having four 15-crown-5 moieties in one of the ligands was synthesized, and its dimerization and magnetic properties were studied in an attempt to utilize the supramolecular aggregation for enhancing the SMM properties. Aggregation of [1]<sup>0</sup> to form [1<sub>2</sub> K<sub>4</sub> ]<sup>4+</sup> in the presence of K<sup>+</sup> ions was studied by using UV/Vis-NIR absorption and NMR spectrosco
The Dy<sup>III</sup> quintuple-decker complex DyCdCdDy and hetero quadruple-decker complex DyCdY were synthesized, and their magnetic properties were compared with those of the quadruple-decker complex DyCdDy. Single-crystal X-ray analysis revealed that the coordination geometries around the Dy<sup>III</sup> ions of DyCdCdDy, DyCdY, and DyCdDy were similar. dc (direct current) magnetic measurements indicated that DyCdCdDy had very weak ferromagnetic Dy<sup>III</sup>-Dy<sup>III</sup> interactions
A clamshell-type terbium(iii)-phthalocyaninato quadruple-decker complex was synthesized. Magnetic measurements revealed that Tb-Tb interactions caused an increase in the magnetic relaxation time and enhanced the SMM properties.
Synthesis, structures, and magnetic properties of α-butoxy-substituted phthalocyaninato double-decker complexes Tb(α-obPc)<sub>2</sub> (1<sup>-</sup>) (α-obPc: dianion of 1,4,8,11,15,18,22,25-octa(n-butoxy)phthalocyaninato) with protonated (1H), deprotonated (1[HDBU]), and diprotonated forms (1H<sub>2</sub><sup>+</sup>) are discussed. X-ray analysis was used to confirm the position of the proton in 1H, and it was revealed that the protonation induced asymmetric distortion in 1H. In contrast, 1[H
In the research field of single-molecule magnets (SMMs), lanthanoid-lanthanoid interactions, so-called f-f interactions, are known to affect the SMM properties, although their magnitudes are small. In this article, an SMM with very weak f-f interactions is reported, and the effects of the interactions on the SMM properties are discussed. X-ray structural analysis of the Dy<sup>III</sup> -Cd<sup>II</sup> -phthalocyaninato sextuple-decker complex (Dy<sub>2</sub> Cd<sub>3</sub> ) reveals that the i
Presented here is a comprehensive study of highly oxidized multiple-decker complexes composed of Tb<sup>III</sup> and Cd<sup>II</sup> ions and two to five phthalocyaninato ligands, which are stabilized by electron-donating n-butoxy groups. From X-ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl-shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was obser
Gd<sup>3+</sup> complexes have been shown to undergo unusual slow magnetic relaxation processes similar to those of single-molecule magnets (SMMs), even though Gd<sup>3+</sup> does not exhibit strong magnetic anisotropy. To reveal the origin of the slow magnetic relaxation of Gd<sup>3+</sup> complexes, we have investigated the magnetic properties and heat capacities of two Gd<sup>3+</sup> -phthalocyaninato triple-decker complexes, one of which has intramolecular Gd<sup>3+</sup> -Gd<sup>3+</sup>
Abstract Molecule‐based magnetic materials are promising candidates for molecular spin qubits, which utilize spin relaxation behavior. Various kinds of transition metal complexes with S =1/2 have been reported to act as spin qubits with long spin‐spin relaxation times ( T 2 ). However, the spin qubit properties of low‐spin Ni(III) complexes are not as well known since Ni(III) compounds are often unstable. We report here the slow magnetic relaxation behavior and T 2 values for three kinds of low‐
Ligand oxidation of single-molecule magnets enhances magnetic relaxations <italic>via</italic> higher energy levels.
Two crystal polymorphs of Ni(cyclam)I<sub>2</sub> (cyclam = 1,4,8,11-tetraazacyclotetradecane) were synthesized, and their magnetic properties were investigated. Temperature-dependent X-ray structural analysis and magnetic measurements revealed gradual spin transition in molecular-crystal polymorph <i>trans</i>-[Ni(cyclam)I<sub>2</sub>] (<b>1a</b>), whereas the zigzag-chain polymorph <i>catena</i>-[Ni(cyclam)(μ-I)]I (<b>1b</b>) did not show an obvious spin transition. The entropy difference betw
Designing molecular complexes as qubits requires understanding properties that contribute to long electron spin-lattice relaxation times. Spin-lattice relaxation was measured as a function of temperature and position in the spectrum for vanadyl tetraphenylporphyrin (VOTPP) in titanyl tetraphenylporphyin (TiOTPP) and zinc tetraphenylporphyrin (ZnTPP) hosts and for nitrido chromium(V) TPP in TiOTPP. <i>T</i><sub>1</sub> also was measured for the vanadyl complexes of octaethylporphyrin (OEP) and te
A robust network structure of single-molecule magnets that exhibits perpendicular magnetic anisotropy preferred for memory devices was constructed utilizing coordination chemistry at the air–liquid interface.
Phase stabilisation elongates spin–lattice relaxation times.
We report an elastic crystal of a copper(II) porphyrinato complex that exhibits slow magnetic relaxations and is a promising candidate for an external-force-responsive spin qubit.
