Magneto-ionic phase control in a quasi-layered donor/acceptor metal–organic framework by means of a Li-ion battery system

Abstract

Electrical magnetism control is realized in a Li-ion battery system through a redox reaction involving ion migrations; “magneto-ionic control”. A quasi-layered metal–organic framework compound with a cross-linked π-conjugated/unconjugated one-dimensional chain motifs composed of electron-donor/acceptor units is developed as the cathode material. A change in magnetic phase from paramagnetic to ferrimagnetic is demonstrated by means of electron-filling control for the acceptor units via insertion of Li+-ions into pores in the material. The transition temperature is as high as that expected for highly π-conjugated layered systems, indicating an extension of π-conjugated exchange paths by rearranging coordination bonds in the first discharge process.

Magnetic Sponge Behavior via Electronic State Modulations

“…A clear distinction between the solvated and desolvated groups was found in local bond lengths in parts of [Ru 2 ] and TCNQMe 2 units, which clearly reflect the oxidation states of units demonstrated in previous work. ,− ,− For the [Ru 2 ] unit, Ru–O eq (O eq = carboxylate oxygen atom), bond distances were quite sensitive to the oxidation state of the [Ru 2 ] unit: 2.06–2.07 Å for [Ru 2 II,II ] and 2.01–2.03 Å for [Ru 2 II,III ] + . The Ru–O eq distances in 1 , 1-dry , 2 , and 2-dry are summarized in Table S2.…”

“…Because PCPs/MOFs protrude because of the flexibility that allows structural deformation to accommodate guest molecules, the change in the magnetic properties in the host framework induced by guest sorption is a promising phenomenon. Indeed, reversible magnetic changes induced by guest molecule accommodations, − including ion accommodations induced by an electrochemical approach, − have been reported so far. These changes are based on a methodology apparently different from those realized by applying external stimuli such as light − and pressure. − Generally, driving forces for guest-induced magnetic modulation (except for the electrochemical approach) have been reported (so far) to be (i) a change in the coordination environment (changes in lattice dimensions or modification of bonds that become magnetic pathways), (ii) malformations of the lattice (e.g., disorder, rotation, and shrinkage/expansion), (iii) structural collapse and recovery (e.g., transformation between crystal and amorphous phases), and (iv) a combination of the first three processes.…”

Magnetic Correlation Engineering in Spin‐Sandwiched Layered Magnetic Frameworks

“…− ) in a 2:1 formula [13–20] is an intriguing target for attempting systematic construction of hybridized layered systems. In such systems, various types of molecules [21–24] or ions [25–28] could be inserted between the magnetic layers to result in flexible charge variations without changing the basic layered framework (Scheme 1 a). [29–32] Among them, π‐conjugated inserted molecules were sandwiched between adjacent TCNQ moieties of the layers with a π‐stacking mode to form a π‐stacked pillared layer framework (π‐PLF) [33] .…”

“…[12] Af amily of 2D layered magnetic compounds composed of paddlewheel-type diruthenium(II,II/II,III) complexes ([Ru 2 II,II ]w ith S = 1a nd [Ru 2 II,III ] + with S = 3/2) and ar adical form of 7,7,8,8tetracyano-p-quinodimethane (TCNQ) derivatives( m 4 -TCNQR x C À ) in a2:1 formula [13][14][15][16][17][18][19][20] is an intriguing target fora ttempting systematicc onstruction of hybridized layered systems. In such systems, various types of molecules [21][22][23][24] or ions [25][26][27][28] could be insertedb etween the magnetic layers to result in flexible charge variationsw ithoutc hanging the basic layered framework (Scheme 1a). [29][30][31][32] Among them, p-conjugated inserted molecules were sandwiched between adjacent TCNQ moieties of the layers with a p-stacking mode to form a p-stacked pillared layer framework (p-PLF).…”

Magnetic Switching by the In Situ Electrochemical Control of Quasi‐Spin‐Peierls Singlet States in a Three‐Dimensional Spin Lattice Incorporating TTF‐TCNQ Salts

“…[3][4][5] Therea re two methods to use the void spaces (i.e.,p ores)i nM OFs/PCPs:b yp re-organizing functional molecules in the pores during the self-assembly syntheticp rocess (for the design of statically controlled functionality), or by insertingf unctional molecules into the pores after framework formationt oa ttempt the guest-induced dynamic control of the functionality.B ased on the formers trategy,b i -or synergistic functions, such as metallic ferromagnets, [6] chiral magnets, [7,8] and switchable ferroelastic transitions, [9] have been demonstrated, in which functionalities in the framework and the molecules or molecular array in the pores mutuallyi nteract to induce as pecific characteristic. [10] Meanwhile, the latter strategy is acurrent growing interest, in which physical properties of frameworks, such as electronic, [11,12] magnetic, [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and spectroscopic properties [31,32] are modulated by guest molecules/ionsi nsertedi nto the nano-sized pores of the frameworks after framework formation.H owever, the development of MOF/PCP materials, where these technical strategies are assembled in as ingle system, is crucial for the creationo fa finely tuned and accessible functional molecular system.F igure 1a shows an example in which at rigger molecule for the activation/inactivationo faframework function is inserted into the pores during the self-assembly process, which inactivates framework function through host-guest interactions (step-A). The trigger molecule is modulated by an externals timulus,o r ac hemical perturbation, to activate the anticipated framework-function (step-B).…”