Three new three-dimensional organic–inorganic hybrid compounds based on PMo12O40n− (n = 3 or 4) polyanions and CuI–pyrazine/CuI–pyrazine–Cl porous coordination polymers

Abstract

Three new organic-inorganic hybrid compounds based on PMo12O40(n-) (n = 3 or 4) polyanions and Cu(I)-pz/Cu(I)-pz-Cl porous coordination polymers: [Cu(I)(pz)]3[PMo(VI)12O40] (1), [Cu(I)(pz)1.5]4[PMo(V)Mo(VI)11O40]·pz·2H2O (2), [Cu(I)3(pz)3Cl][Cu(I)2(pz)3(H2O)][PMo(V)Mo(VI)11O40] (3) (pz = pyrazine) have been hydrothermally prepared and characterized by elemental analysis, IR, TG, XRD, XPS and single-crystal X-ray diffraction. Compound 1 presents a three-dimensional Cu(I)-pz framework with cube-like chambers, into which PMo(VI)12O40(3-) Keggin ions are incorporated. Compound 2 shows a three-dimensional sandwich-like framework, and PMo(V)Mo(VI)11O40(4-) polyanions are located in the octagonal voids of every two-dimensional Cu(I)-pz 4(1)8(2) network structure. Compound 3 exhibits a two-dimensional Cl-bridged Cu(I)-pz-Cl double-layer structure, and two kinds of PMo(V)Mo(VI)11O40(4-) polyanions as bridging linkers connect two adjacent double-layers to form a three-dimensional organic-inorganic framework through Cu(I)-O bonds. Additionally, their electrochemical characters, electrocatalytic behaviors and solid state fluorescent properties at room temperature have been investigated in detail.

A survey of interactions in crystal structures of pyrazine-based compounds

“…16b). Again, hydrogen bonding, such as C-HÁ Á ÁO interactions, that surround the [PMo 12 O 40 ] 3À units need to be considered (Qi et al, 2013).…”

Two POM-based compounds containing Zn-capped Keggin anions as decent heterogeneous catalysts for sulfur oxidation and CO2 cycloaddition reactions

“…Nevertheless, POMs are also conventionally soluble in different solvents, which may worrisomely impede reusing and recycling on most occasions. [23][24][25][26] By introducing organic ligands, Zn-capped Keggin-type POM hybrids break the abovementioned limits. [27][28][29][30] In 2021, Ma's group 31,32 successfully synthesized several POM-based organic-inorganic hybrids containing Keggin-type [PMo 12 O 40 ] 3− anions, which show desirable catalytic activity in sulfur removal with great stability.…”

Polyoxometalate-Based Organic–Inorganic Hybrids as Heterogeneous Catalysts for Cycloaddition of CO2 with Epoxides and Oxidative Desulfurization Reactions

“…Polyoxometalates (POMs), a type of polymetallic oxygen cluster with excellent thermal stability, − are widely used in the fields of magnetism, biomedicine, and catalysis. − However, POMs are typically soluble in water and various organic solvents, − which greatly limits their further development in catalysis owing to the separation difficulty from the reaction system . POM-based inorganic–organic hybrids, as a type of heterogeneous catalyst, break the above-mentioned limits . They feature high stability and diverse structures and are frequently employed in various catalytic reactions. − …”