All-inorganic ferric wheel based on hexaniobate-anion linkers. Issue 22 (20th May 2022)

• Record Type: Journal Article
• Authors: Baranov, Mark; Polin, Libi; Leffler, Nitai; Leitus, Gregory; Shames, Alexander I.; Weinstock, Ira A.
• Is Part Of: Dalton transactions. Volume 51:Issue 22(2022)
• Page Start: 8600
• Page End: 8604
• Publication Date: 2022-05-20
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d2dt00971d
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Eight hexaniobate cluster-anions link eight Fe(iii ) ions that are antiferromagnetically coupled through long-distance interactions in an all-inorganic ferric wheel. Abstract : Utilizing the inherent ability of Lindquist-type hexaniobate cluster-anions, [Nb6 O19 ] 8−, to serve as oxo-donor ligands in complexes with transition-metal cations, we report the synthesis and characterization of the first all-inorganic "ferric" wheel, Li48 [(Nb6 O19 )8 Fe8 (OH)8 ]·88H2 O, comprised of eight Fe atoms linked by eight hexaniobate cluster-anion ligands. Bond valence sum analysis of the X-ray structure and the synthesis conditions themselves indicate that the Fe atoms are in the +3 oxidation state. This is confirmed by magnetic susceptibility and electron paramagnetic resonance (EPR) measurements which indicate the presence of high spin ( S = 5/2) Fe(iii ) ions. In addition, magnetic susceptibility measurements reveal long-range superexchange antiferromagnetic interactions between the hexaniobate-ligand separated Fe 3+ ions ( J = −0.22 cm −1 ). More generally, the results suggest the use of hexaniobate cluster-anions as linkers in the synthesis of other two- or three-dimensional polyoxometalate framework structures.