Ni^II₃₆‐Containing 54‐Tungsto‐6‐Silicate: Synthesis, Structure, Magnetic and Electrochemical Studies

Abstract

The 36‐NiII‐containing 54‐tungsto‐6‐silicate, [Ni36(OH)18(H2O)36(SiW9O34)6]6− (Ni36) was synthesized by a simple one‐pot reaction of the Ni2‐pivalate complex [Ni2(μ‐OH2)(O2CCMe3)4(HO2CCMe3)4] with the trilacunary [SiW9O34]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 {NiII6SiW9} 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 WVI/V couple, whereas the second reduction is irreversible attributed to the NiII/0 couple.

Synergic coordination of multicomponents for the formation of a {Ni30} cluster substituted polyoxometalate and its in situ assembly

“…S2a†). 25 It is worth emphasizing that the six {Ni 6 } clusters in [Ni 6 POM] 6 are discrete despite the use of a dinuclear coordination complex [Ni 2 (μ-OH 2 )(O 2 CCMe 3 ) 4 (HO 2 CCMe 3 ) 4 ] as the nickel source. In [Ni 6 POM] 6 , neighbouring Ni 6 POMs connect with each other via four-fold Ni–OW and two-fold Ni–O–W linkers, attesting to the high activity of the O atoms on the surface of the POM (Fig.…”

Polyoxometalates-Functionalized Electrodes for (Photo)Electrocatalytic Applications: Recent Advances and Prospects

“…Besides, by changing the tricavant-type structure for the B-α-[P 2 W 15 O 56 ] 12– , derived from the Wells–Dawson anion, the condensation process led to a large tetrameric species containing the central [Ni 14 (OH) 6 (H 2 O) 10 (HPO 4 ) 4 ] core . Last, very large and spectacular Ni 25 - and Ni 36 -hexameric assemblies were reported nicely exemplifying the common feature of such a class of mixed-metal compounds wherein the POM subunits act as a modulator within the condensation of the 3d metallic cations, allowing the formation of well-defined polyoxo­(hydroxo)­aquo clusters {M x O y (OH) z (H 2 O) w } n + surrounded by the protecting POM subunits . Using similar approaches, many Co-, − Mn-, − Fe-, ,− or Cu-containing − POMs have been reported, illustrating the high structural diversity in the resulting mixed metal arrangements in relationship with the synthesis conditions and the stereochemical and coordinating properties of the preformed POM subunits.…”

High-Nuclear Ni-Substituted Poly(polyoxometalate) Containing an Anderson-like {Cs7} Cluster

“…Among them, Ni-substituted POMs has been extensively studied because of their excellent performance in magnetism and catalysis. − So far, a large number of Ni-substituted POMs have been reported, but most of them comprise less than 10 Ni 2+ centers. Typical examples of Ni-substituted POMs containing large Ni-oxo clusters with more than 10 Ni 2+ centers include [Ni 12 (OH) 9 (PO 4 ) 4 (SiW 9 O 34 )­{W 4 O 10 (OH)­(PO 2 (OH) 2 ) 2 (SiW 9 O 34 ) 2 }] 26– , [Ni 12 O 9 (BO 3 ) 3 PO 4 -(SiW 9 O 34 ) 3 ] 36– , [Ni 12 (OH) 9 WO 4 ­(W 7 O 26 (OH)­(PW 9 O 34 ) 3 ] 25– , [Ni 14 (OH) 6 (H 2 O) 10 ­(HPO 4 ) 4 (P 2 W 15 O 56 ) 4 ] 34– , [{Ni 4 (OH) 3 (PO 4 )} 4 -(PW 9 O 34 ) 4 ] 28– , [{Ni 4 (OH) 3 ( A -α-SiW 9 O 34 )} 4 ­(OOC­(CH 2 ) 3 COO) 6 ] 32– , [Ni 12 (OH) 9 (CO 3 ) 3 (PO 4 )­(SiW 9 O 34 ) 3 ] 24– , [Ni 13 (H 2 O) 3 (OH) 9 (PO 4 ) 4 (SiW 9 O 34 ) 3 ] 25– , and [Ni 25 (H 2 O) 2 OH) 18 (CO 3 ) 2 (PO 4 ) 6 (SiW 9 O 34 ) 6 ] 50– .…”