東北大学 · Materials Science
히토시 미야사카 교수의 연구실은 주로 다핵 과도금속 복합체를 기반으로 한 나노자기재료, 특히 단일사슬 자성체(Single-Chain Magnets, SCMs)와 단일분자자성체(Single-Molecule Magnets, SMMs)의 설계 및 기초 물성 연구를 중심으로 하고 있습니다. 특히 망간(III) 이온을 포함한 다핵 복합체를 이용해 자성 이성질성과 느린 자화 리프레시를 유도하는 구조적 제어 기법을 개발하며, 전자 이동과 자성 상호작용을 연계한 기능성 금속 유기 프레임워크(D/A-MOFs)의 설계도 진행 중입니다. 이들의 연구는 고도로 제어된 나노자기 재료의 설계 원리를 제시하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
The reaction between the [Mn(BS)(H2O)]+ monomeric and [Mn2(μ-BS)2(H2O)2]2+ dimeric cations and [Fe(CN)6]3- gave rise to cation−anion interaction via the formation of [FeC⋮NMn] bridges. Depending on the nature of the Schiff base and regardless of the stoichiometry used, either the trimeric anion [{Mn(BS)}2{Fe(CN)6}]- (BS = 3-MeOsalen, 6; 5-Clsalen, 7; 5-Brsalen, 8; salcy, 10) or the pentameric cation [{Mn(BS)}4{Fe(CN)6}]+ (BS = saltmen, 9) is formed, which has been assembled by the K+ cation or t
Slow relaxation of the magnetization (i.e., "magnet-like" behavior) in materials composed of magnetically isolated chains was observed for the first time in 2001. This type of behavior was predicted in the 1960s by Glauber in a chain of ferromagnetically coupled Ising spins (the so-called Glauber dynamics). In 2002, this new class of nanomagnets was named single-chain magnets (SCMs) by analogy to single-molecule magnets that are isolated molecules displaying related superparamagnetic properties.
Slow relaxation of the magnetization reveals the single-molecule magnetic behavior of [Mn2(saltmen)2(ReO4)2] (saltmen2−=N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminate), a simple, out-of-plane MnIII dimeric complex containing a [MnIII(μ-O)2MnIII] core (see structure shown, Mn brown, O red, N blue, Re pink). The two anisotropic MnIII ions are ferromagnetically coupled, which induces an ST=4 ground state.
Three two-dimensional (2D) network compounds based on Mn(III)/Mn(II) tetranuclear single-molecule magnets (SMMs) connected by dicyanamide (dcn-) linkers have been synthesized: [Mn4(hmp)4(Hpdm)2(dcn)2](ClO4)2 x 2 H2O x 2 MeCN (2), [Mn4(hmp)4Br2(OMe)2(dcn)2] x 0.5 H2O x 2 THF (3), [Mn4(hmp)6(dcn)2](ClO4)2 (4), where Hhmp and H2pdm are 2-hydroxymethylpyridine and pyridine-2,6-dimethanol, respectively. The [Mn4]/dcn- system appears very versatile, but enables its chemistry to be rationalized by a fi
Charge transfer (CT) of D(0)A(0) ↔ D(δ+)A(δ-) not only involves an electron transfer from D to A, but also generates a new spin set of S = 1/2 spins with an exchange interaction. Therefore, the control of CT in multidimensional frameworks could be an efficient way to design electronically/magnetically functional materials. The use of redox-active metal complexes as D and/or A building blocks expands the variety of such D/A frameworks with the formulation of D(m)A(n) (m, n ≥ 1), permitting the de
A series of single-chain magnets, [Mn2(saltmen)2Ni(pao)2(L)2](A)2 (saltmen(2-)=N,N'-(1,1,2,2-tetramethylethylene) bis(salicylideneiminate), pao-=pyridine-2-aldoximate; A-=ClO4- with L=4-picoline; 2, 4-tert-butylpyridine; 3, N-methylimidazole; 4, and L=pyridine with A-=BF4-; 5, PF6-; 6, ReO4-; 7), was prepared by reactions between MnIII dimer units, i.e., [Mn2(saltmen)2(H2O)2](A)2 (A-=ClO4-, BF4-, PF6-) or Mn2(saltmen)2(ReO4)2, and NiII monomeric units, i.e., Ni(pao)2(L)2, in methanol/water media
The bulk photovoltaic effect (BPVE) is a promising optoelectronic phenomenon for generating a steady-state photocurrent without a bias voltage. Nevertheless, the simple and rational design of materials exhibiting the BPVE remains an important topic in the relevant fields. Here, we report the observation of the BPVE in a simple chiral-polar pair of layered perovskite-type lead iodides in the crystal space group of <i>P</i>1 (#1), which were synthesized by assembling <i>R-</i> and <i>S</i>-chiral
π delocalization throughout the extended layers of two-dimensional network polymers of the type [{M2(O2CCF3)4}2(TCNQ)⋅3 (C7H8)]∞, which consist of RuII,RuII and RhII,RhII complexes coordinated to TCNQ molecules, is evident from the available structural (see picture for Ru analogue) and spectroscopic data. TCNQ=7,7,8,8-tetracyano-p-quinodimethane.
The discrete trinuclear complex [(NEt4){Mn(H2O)(5-Cl-salen)}2{Fe(CN)6}]·H2O, 3, and a two-dimensional heterometal assembly [(NEt4){Mn(5-Cl-salen)}2{Fe(CN)6}]n, 4, have been prepared (NEt4 = tetraethylammonium, 5-Cl-salen = N,N‘-ethylenebis(5-chlorosalicylidene)aminato) dianion). Compound 4 crystallizes in the monoclinic space group P21/c with cell dimensions of a = 13.104(3) Å, b = 12.861(3) Å, c = 15.526(2) Å, β = 105.98(1)°, Z = 2 and is isostructural to the previously synthesized metamagnetic
The isostructural series of two-dimensional (2-D) fishnet-type network compounds, [{Ru(2)(O(2)CCF(3))(4)}(2)(TCNQR(x))] x n(solv) (R(x) = H(4), 1; Br(2), 2; Cl(2), 3; F(2), 4; F(4), 5), has been synthesized from the reactions of a paddlewheel diruthenium(II, II) complex, [Ru(2)(II,II)(O(2)CCF(3))(4)], and neutral TCNQ derivatives (TCNQR(x) = 2,3,5,6- or 2,5-halogen-substituted 7,7,8,8-tetracyanoquinodimethane) under anaerobic conditions. Corresponding Rh compounds 1-Rh-5-Rh, which are diamagneti
Six Mn(III) quadridentate Schiff base compounds with N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminato) dianion (saltmen2−) and N,N′-(1,1,2,2-tetramethylethylene)bis(naphthylideneiminato) dianion (naphtmen2−) have been prepared and structurally characterized: [Mn(saltmen)(H2O)]ClO4 (1), [Mn(naphtmen)(H2O)]ClO4 (2), [Mn(saltmen)(NCS)] (3), [Mn(naphtmen)(NCS)] (4), [Mn(saltmen)(Cl)] (5) and [Mn(naphtmen)(Cl)] (6). Among them, 1 and 2 form phenolate-bridged out-of-plane dimers with Mn–Ophen
An alternated 1:1 chain compound of a Mn(III) salen derivative and the TCNQ monoradical was synthesized: [Mn(5-TMAMsaltmen)(TCNQ)](ClO(4))(2) (1) (TCNQ=tetracyano-p-quinodimethane; 5-TMAMsaltmen=N,N'-(1,1,2,2-tetramethylethylene) bis(5-trimethylammoniomethylsalicylideneiminato)). Compound 1 has a zigzag chain structure packed with adjacent chains with an interchain MnMn distance of over 8 Angatrom. As compound 1 contains no crystallization solvent, the void spaces between chains are occupied onl
Nanosized molecular magnetic materials such as single-molecule magnets and single-chain magnets are recent attractive research targets in the fields of materials chemistry and physics, not only because of their fundamental fascination, but also because of their potential applications as ultimate memory devices or in quantum computations. In this paper, we give our personal perspectives on these materials. In particular "magnetic assemblies of single-molecule magnets", in which inter-molecular in
[Mn(BS)(H2O)]ClO4 and [NEt4]3[Fe(CN)6] react in methanol or ethanol to give a binuclear [NEt4]2[{Mn(BS)(S)}{Fe(CN)6}], 1, three trinuclear [NEt4][{Mn(BS)(S)}2{Fe(CN)6}], 2−4, and a pentanuclear [Mn(BS)(S)]4[Fe(CN)6]ClO4, 5, heterometal complex, depending on the nature of the quadridentate Schiff-base ligands and regardless of the stoichiometric ratio of the precursor components (BS = saldmen = N,N'-(1,1-dimethylethylene)bis(salicylideneiminato) dianion, S = H2O for 1; BS = rac-salmen = rac-N,N'-