NiII36‐Containing 54‐Tungsto‐6‐Silicate: Synthesis, Structure, Magnetic and Electrochemical Studies. Issue 61 (22nd September 2021)

• Record Type: Journal Article
• Authors: Goura, Joydeb; Bassil, Bassem S.; Ma, Xiang; Rajan, Ananthu; Moreno‐Pineda, Eufemio; Schnack, Jürgen; Ibrahim, Masooma; Powell, Annie K.; Ruben, Mario; Wang, Jingjing; Ruhlmann, Laurent; Kortz, Ulrich
• Is Part Of: Chemistry. Volume 27:Issue 61(2021)
• Page Start: 15081
• Page End: 15085
• Publication Date: 2021-09-22
• Subjects: Electrochemistry -- magnetic properties -- nickel -- polyoxometalates -- structure elucidation; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202102973
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The 36‐Ni II ‐containing 54‐tungsto‐6‐silicate, [Ni36 (OH)18 (H2 O)36 (SiW9 O34 )6 ] 6− (Ni36 ) was synthesized by a simple one‐pot reaction of the Ni2 ‐pivalate complex [Ni2 ( μ ‐OH2 )(O2 CCMe3 )4 (HO2 CCMe3 )4 ] with the trilacunary [SiW9 O34 ] 10− polyanion precursor in water and structurally characterized by a multitude of physicochemical techniques including single‐crystal XRD, FTIR, TGA, elemental analysis, magnetic and electrochemical studies. Polyanion Ni36 comprises six equivalent {Ni II 6 SiW9 } units which are linked by Ni−O−W bridges forming a macrocyclic assembly. Magnetic studies demonstrate that the {Ni6 } building blocks in Ni36 remain magnetically intact while forming a hexagonal ring with antiferromagnetic exchange interactions between adjacent {Ni6 } units. Electrochemical studies indicate that the first reduction is reversible and associated with the W VI/V couple, whereas the second reduction is irreversible attributed to the Ni II/0 couple. Abstract : The 36‐Ni II ‐containing 54‐tungsto‐6‐silicate, [Ni36 (OH)18 (H2 O)36 (SiW9 O34 )6 ] 6− (Ni36 ) was discovered and shown to contain more nickel centers than any other polyoxometalate (POMs) known to date. Polyanion Ni36 comprises six equivalent {Ni II 6 SiW9 } units which are linked by Ni−O−W bridges forming a macrocyclic assembly. Magnetic studies indicate antiferromagnetic communication between the six {Ni6 } subunits. Electrochemical studies indicate that the first reduction is reversible and associated to the W VI/V couple while the second reduction is irreversible and associated to the Ni II/0 couple.