Order in disorder: Solution and solid-state studies of [M III 2 M II 5] wheels (MIII = Cr, Al; MII = Ni, Zn)

Fraser, H.W.L. ; Nichol, G.S. ; Uhrín, D. ; Nielsen, U.G. ; Evangelisti, M. (Universidad de Zaragoza) ; Schnack, J. ; Brechin, E.K.

Resumen: A family of heterometallic Anderson-type ''wheels'' of general formula [MIII2MII5(hmp)12](ClO4)4 (where MIII = Cr or Al and MII = Ni or Zn giving [Cr2Ni5] (1), [Cr2Zn5] (2), [Al2Ni5] (3) and [Al2Zn5] (4); hmpH = 2-pyridinemethanol) have been synthesised solvothermally. The metallic skeleton common to all structures describes a centred hexagon with the MIII sites disordered around the outer wheel. The structural disorder has been characterised via single crystal X-ray crystallography, 1-3D 1H and 13C solution-state NMR spectroscopy of the diamagnetic analogue (4), and solid-state 27Al MAS NMR spectroscopy of compounds (3) and (4). Alongside ESI mass spectrometry, these techniques show that structure is retained in solution, and that the disorder is present in both the solution and solid-state. Solid-state dc susceptibility and magnetisation measurements on (2) and (3) reveal the Cr-Cr and Ni-Ni exchange interactions to be JCr-Cr = -1 cm-1 and JNi-Ni, r = -5 cm-1, JNi-Ni, c = 10 cm-1. Fixing these values allows us to extract JCr-Ni, r = -1.2 cm-1, JCr-Ni, c = 2.6 cm-1 for (1), the exchange between adjacent Ni and Cr ions on the ring is antiferromagnetic and between Cr ions on the ring and the central Ni ion is ferromagnetic.

Idioma: Inglés

DOI: 10.1039/c8dt00685g

Año: 2018

Publicado en: Dalton Transactions 47, 34 (2018), 11834-11842
ISSN: 1477-9226

Factor impacto JCR: 4.052 (2018)

Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 7 / 45 = 0.156 (2018) - Q1 - T1

Factor impacto SCIMAGO: 1.12 - Inorganic Chemistry (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2015-68204-R

Tipo y forma: Article (Published version)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)