Metamagnetism with TN = 97 K in a layered assembly of paddlewheel [Ru2] units and TCNQ: an empirical rule for interlayer distances determining the magnetic ground state. (17th January 2018)

• Record Type: Journal Article
• Authors: Kosaka, Wataru; Itoh, Masahisa; Miyasaka, Hitoshi
• Is Part Of: Materials chemistry frontiers. Volume 2:Number 3(2018)
• Page Start: 497
• Page End: 504
• Publication Date: 2018-01-17
• Subjects: Materials science -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1039/c7qm00534b
• Languages: English
• ISSNs: 2052-1529

Abstract

Abstract : A new layered antiferromagnet was synthesized from the reaction of a paddlewheel diruthenium(ii, ii ) complex with a TCNQ derivative. The complex has a short interlayer distance and forms part of a series of layered antiferromagnets. Abstract : A donor (D)/acceptor (A) assembly reaction of the paddlewheel-type diruthenium(ii, ii ) complex [Ru2 ( m -ClPhCO2 )4 (THF)2 ] ( m -ClPhCO2 − = meta -chlorobenzoate; abbreviated hereafter as [Ru2 ]) with 2, 5-dimethoxy-7, 7, 8, 8-tetracyano- p -quinodimethane (TCNQ(MeO)2 ) in a dichloromethane (DCM)/1, 1, 2, 2-tetrachloroethane (TCE) solvent system led to the formation of a two-dimensional layered D2 A compound with crystallization solvents located between layers: [{Ru2 ( m -ClPhCO2 )4 }2 {TCNQ(MeO)2 }]·3.3DCM·2TCE (1 ). Compound1 undergoes an intra-lattice one-electron transfer to form a charge-distributed state with the formula [{RuII, III2} + –TCNQ˙ − –{RuII, II2}] with intra-layer ferrimagnetic spin ordering through dπ*–pπ* orbital overlap that results in ferrimagnetic arrangement with antiferromagnetic interactions over heterospins of S = 1 for [RuII, II2] and S = 3/2 for [RuII, III2] via S = 1/2 for TCNQ˙ − . Consequently, because of the presence of interlayer antiferromagnetic interactions, 1 has an antiferromagnetic ground state with T N = 97 K. On applying a field of less than 0.5 T, a spin flip is induced, yielding a field-induced ferrimagnet (a type of metamagnet) with a large coercive field of 1.2 T at 1.8 K. Compound1 has interlayer translational ( i.e., interlayer [Ru2 ]⋯[Ru2 ] or TCNQ⋯TCNQ distance) ( l 2 ) and interlayer vertical ( l 1 ) distances of 10.30 and 9.82 Å, respectively. By comparison of the magnetostructural correlations of this type of layered magnet, this class of antiferromagnets, including1, reveal a trend of having l 2 ≤ 10.3 Å.