A Pyridazine-Bridged Sandwiched Cluster Incorporating Planar Hexanuclear Cobalt Ring and Bivacant Phosphotungstate


A planar hexanuclear cobalt ring was clamped by two bivacant α<sub>1</sub>-[PW<sub>10</sub>O<sub>37</sub>]<sup>9–</sup> with the assistance of the pyridazine bridges to form a novel sandwiched Co­(II)-polyoxometalate cluster compound, [Na­(H<sub>2</sub>O)<sub>6</sub>]­[Co<sub>3</sub>(OH) (pydz)<sub>4</sub>(H<sub>2</sub>O)<sub>7</sub>]­[Co<sub>6</sub>(PW<sub>10</sub>O<sub>37</sub>)<sub>2</sub>(pydz)<sub>4</sub>(H<sub>2</sub>O)<sub>6</sub>]·43H<sub>2</sub>O (<b>1</b>; pydz = pyridazine).This cluster was identified by X-ray single-crystal diffraction, elemental analysis, Fourier transform IR and UV–visible spectroscopies, and cyclic voltammetry (CV). Structural analysis reveals that <b>1</b> comprises a hexahydrated sodium, a trinuclear [Co<sub>3</sub>(OH) (pydz)<sub>4</sub>(H<sub>2</sub>O)<sub>7</sub>]<sup>5+</sup> cationic cluster, and an anionic [Co<sub>6</sub>(PW<sub>10</sub>O<sub>37</sub>)<sub>2</sub>­(pydz)<sub>4</sub>(H<sub>2</sub>O)<sub>6</sub>]<sup>6–</sup> sandwiched cluster, thus giving an intrinsical intercluster compound. The isolation of such cluster was dependent on the in situ transformation of trivacant [α-P<sub>2</sub>W<sub>15</sub>O<sub>56</sub>]<sup>12–</sup> to α<sub>1</sub>-[PW<sub>10</sub>O<sub>37</sub>]<sup>9–</sup> under the hydrothermal condition. The CV shows reversible multielectron waves from the redox of W<sup>VI</sup> in <b>1</b>. Cluster <b>1</b> exhibits remarkable electrocatalytic activity toward the reduction of nitrite. Magnetism studies indicated a weak anti-ferromagnetic exchange interaction between Co­(II) ions within <b>1</b>

Similar works

Full text

oai:figshare.com:article/3749382Last time updated on 2/12/2018

This paper was published in FigShare.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.