Anisotropic exchange interaction and field-induced SMM behaviour in a mixed valence {CoII4CoIII2} complex. Issue 4 (12th January 2021)

• Record Type: Journal Article
• Authors: Cabrosi, Daiana; Cruz, Carlos; Paredes-García, Verónica; Alborés, Pablo
• Is Part Of: Dalton transactions. Volume 50:Issue 4(2020)
• Page Start: 1402
• Page End: 1412
• Publication Date: 2021-01-12
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt03075a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : We report a combined computational and experimental study of SMM behaviour in a mixed valent {CoIII2CoII4} complex with anisotropic exchange interactions. Abstract : We are reporting the synthesis and structural characterization of a new hexanuclear Co(ii )/Co(iii ) complex starting from a versatile pivalate cobalt precursor and the racemic mixture of a chelating Schiff base type ligand. The main [CoII4CoIII2(μ3 -OH)2 (μ-OR)2 (μ-OR′)2 (μ-OR′′)2 ] 6+ core is unprecedented and exhibits an inversion center that affords only two unique Co(ii ) sites. We performed DC and AC magnetic measurements and analysed them in terms of the anisotropic exchange of ground Kramers doublets at each Co(ii ) site due to their unquenched angular orbital contribution to the magnetic moment. Quantum computations support the experimental data treatment. The interplay of dominant antiferromagnetic exchange, inversion symmetry and a non-collinear main quantization axis affords an exchange energy spectrum with mostly non-magnetic states. Nevertheless, field induced SMM behaviour is observed at 1500 Oe and below 3 K which might be explained by the relaxation of the first excited magnetic state (which is populated enough) through the next closest excited state. The Orbach and/or Raman mechanism could be operative from the experimental and quantum computed results.