Ni^II ₃₆ -Containing 54-Tungsto-6-Silicate: Synthesis, Structure, Magnetic and Electrochemical Studies.

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.

SUBMITTER: Goura J 

PROVIDER: S-EPMC8596682 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature