Slow Magnetic Relaxation in a Co2Dy Trimer and a Co2Dy2 Tetramer. Issue 6 (22nd February 2021)

• Record Type: Journal Article
• Authors: Modak, Ritwik; Sikdar, Yeasin; Gómez‐García, Carlos J.; Benmansour, Samia; Chatterjee, Sudipta; Goswami, Sanchita
• Is Part Of: Chemistry, an Asian journal. Volume 16:Issue 6(2021)
• Page Start: 666
• Page End: 677
• Publication Date: 2021-02-22
• Subjects: Single-ion magnet -- Single-molecule magnet -- Slow relaxation -- Co(III)−Dy(III) complexes -- Schiff base ligands; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202001468
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: The combination of Co(III) and Dy(III) with a compartmental Schiff base ligand (H3 L=3‐[(2‐Hydroxy‐3‐methoxy‐benzylidene)‐amino]‐propane‐1, 2‐diol), presenting three different coordinating pockets, has allowed the synthesis of two novel Co(III)−Dy(III) complexes: [Co2 Dy(HL)4 ]NO3 ⋅ 2CH3 CN (1 ), a rare example of trinuclear linear Co III 2 Dy III complex (and the first with slow relaxation of magnetization in absence of a DC field) and [Co2 Dy2 (μ3 −OH)2 (HL)2 (OAc)6 ] ⋅ 4.6H2 O (2 ), the first tetranuclear Co III 2 Dy III 2 cluster with a rhomb‐like structure where the Co(III) ions are connected along the short diagonal of the rhomb. 1 presents two different relaxation processes: a fast relaxation dominated by Quantum tunnelling (QT) and a slow relaxation with an energy barrier of 40 K. 2 shows two close relaxation processes without applied DC fields that follow QT and Orbach mechanisms whereas for HDC =500 Oe, the QT is cancelled and a direct term appears. Here we present the synthesis, X‐ray structure and magnetic characterization of these two Co(III)−Dy(III) single‐ion/molecule magnets. Abstract : A Co III 2 Dy III trimer and a Co III 2 Dy III 2 tetrame r have been synthesized from a multi pocket Schiff base ligand. Both exhibit slow magnetic relaxation in the absence of DC field, Co III 2 Dy III being the first example in the literature. Co III 2 Dy III is a rare example of a linear trinuclear species whereas rhomb‐like Co III 2 Dy III 2 represents the first instance where Co III ions are connected along the short diagonal of the rhomb.