Temperature-Dependent Organic Functionalization of {Ni6PW9} Species: from Isolated Clusters to 1D Chain

Stabilization of Ni-containing Keggin-type polyoxometalates with variable oxidation states as novel catalysts for electrochemical water oxidation

The development of new recyclable and inexpensive electrochemically active species for water oxidation catalysis is the most crucial step for future utilization of renewables. Particularly, transition metal complexes containing internal multiple, cooperative metal centers to couple with redox catalysts in the inorganic Keggin-type polyoxometalate (POM) framework at high potential or under extreme pH conditions would be promising candidates. However, most reported Ni-containing POMs have been highly unstable towards hydrolytic decomposition, which precludes them from application as water oxidation catalysts (WOCs). Here, we have prepared new tri-Ni-containing POMs with variable oxidation states by charge tailored synthetic strategies for the first time and developed them as recyclable POMs for water oxidation catalysts. In addition, by implanting corresponding POM anions into the positively charged MIL-101(Cr) metal-organic framework (MOF), the entrapped Ni2+/Ni3+ species can show complete recyclability for water oxidation catalysis without encountering uncontrolled hydrolysis of the POM framework. As a result, a low onset potential of approximately 1.46 V vs. NHE for water oxidation with stable WOC performance is recorded. Based on this study, rational design and stabilization of other POM-electrocatalysts containing different multiple transition metal centres could be made possible.

Two new hexa-Ni-substituted polyoxometalates in the form of an isolated cluster and 1-D chain: syntheses, structures, and properties

Two new hexa-Ni-substituted polyoxometalates are made and characterized, exhibiting electrochemical performance and photocatalytic activity for the degradation of organic dyes under UV irradiation.

Magnetic dimensionality and the crystal structure of two copper(ii) coordination polymers containing Cu6 and Cu2 building units

The preparation, structural characterization, EPR spectroscopy and magnetic structural correlation of two Cu(ii) coordination polymers are reported.

Steam-assisted assemblies of {Ni6PW9}-based inorganic–organic hybrid chains: synthesis, crystal structures and properties

Three hexa-Ni-substituted Keggin phosphotungstate chains have been obtained through the SAC method, where H₂N-bdc and unprecedented {(Ni₆PW₉)PW₁₂} is reported for the first time.

The main progress over the past decade and future outlook on high-nuclear transition-metal substituted polyoxotungstates: from synthetic strategies, structural features to functional properties

In this article, we discuss the synthetic methodologies, structural diversities and relevant properties of the high-nuclear TMSPTs reported in the past decade.