Assembly of two new polyoxometalate-templated supramolecular compounds by utilizing flexible 1,4-bis(pyrazol-1-ylmethyl)benzene ligand

Abstract

Two new polyoxometalate-templated supramolecular compounds, [Cu^I₄(bpmb)₄][PMo^VI₁₁Mo^VO₄₀] (1) and [Cu^I₄(bpmb)₄SiW₁₂O₄₀] (2) (bpmb = 1,4-bis(pyrazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by routine methods. Structural analysis shows that in 1, there exist crown-like [Cu^I₄(bpmb)₄] coordination macrocycles, and the Keggin polyanions [PMo ^VI₁₁Mo^VO₄₀]⁴⁻ (abbr. as PMo₁₂), which direct the crown-like macrocycle to form a 3-D supramolecular framework. In 2, there exist unusual meso-helix chains, and these chains are mutually interlaced in a wave–trough pattern, but without intersection resulting in a multi-cavity layer, in which the [SiW₁₂O₄₀]⁴⁻ (abbr. as SiW₁₂) clusters as guest molecules occupy the cavities of the layers. The distinct structural features of the two compounds suggest that Keggin polyanions should play a significant role in the process of assembly. Electrocatalytic properties of 1 and 2 were investigated.

Graphical Abstract

Two new POM-templated supramolecular compounds with good electrocatalytic activities toward reduction of iodate have been obtained, which shows that Keggin anions should play a significant role in the process of assembly.

Keywords:

• Keggin
• Polyoxometalate template
• Crown-like macrocycle
• Electrocatalytic properties

Additional information

Funding

Funding. This work was financially supported by the Foundation of Education Committee of Heilongjiang [grant number 12521072].