Step-by-Step Strategy from Achiral Precursors to Polyoxometalates-Based Chiral Organic–Inorganic Hybrids

Abstract

Using two types of triol ligands, several novel asymmetrically triol-functionalized Anderson organic hybrids have been efficiently synthesized in high purity and good yields via a convenient two-step esterification reaction. These organic-inorganic hybrids are chiral and can be spontaneously resolved with suitable solvents. Their molecular and crystal structures have been confirmed by single-crystal X-ray diffraction studies. Stable solid-state chirality of the corresponding enantiopure crystals has also been confirmed definitively by CD spectra. Interestingly, these organic-inorganic hybrids possess a layer-by-layer structure, forming solvent-accessible nanoscale chiral channels via a 1D infinite helical chain substructure. TGA measurements indicated that the species of the central heteroatoms significantly effects the stability of these compounds.

The Anderson–Evans polyoxometalate: From inorganic building blocks via hybrid organic–inorganic structures to tomorrows “Bio-POM”

“…Instead asymmetric products were formed in both cases. Compared with previously reported methods for the isolation of asymmetric products explored for the Mn III Mo 6 system [85,184], this and similar procedures [171] are more controllable since it does not rely on re-arrangement of octamolybdate, save time, give high purity and good yield [188]. Further post-functionalization on asymmetrically functionalized POMs (Figure 7, B5) can be selective depending on e.g.…”

“…The ability to decorate Anderson-Evans POMs in a step-by-step fashion with two different tris-ligands on each side (Figure 7, B2 and B4) can be prepared through a hydrothermal procedure by using water as solvent [171] or by refluxing in hot ethanol [188] giving asymmetrical double-sided products. The hydrothermal method was demonstrated with Cr III Mo 6 whereas refluxing in hot ethanol was achieved with Cr III Mo 6 , Al III Mo 6 and Mn III Mo 6 systems (Figure 7, B2 and B4) in a step-by-step fashion by refluxing.…”

Yolk–shell microspheres assembled from Preyssler‐type NaP5W30O11014− polyoxometalate and MIL‐101(Cr) metal–organic framework: A new inorganic–organic nanohybrid for fast and selective removal of cationic organic dyes from aqueous media

“…The strong attraction of POM polyanions to cationic dyes suggests that they are potential and suitable adsorbents for selectively capturing cationic dyes. However, there are still obvious disadvantages for such POMs as adsorbents, such as (1) their relatively small surface area which seriously obstructs accessibility to the active sites and (2) their high solubility in aqueous solution which means that they cannot be reused and recycled in the process of wastewater treatment . To overcome these drawbacks, metal–organic frameworks (MOFs) have been used for anchoring of POMs to create hybrid heterogeneous materials.…”

Magnetically Recyclable Fe3O4/GO-NH2/H3PMo12O40 Nanocomposite: Synthesis, Characterization, and Application in Selective Adsorption of Cationic Dyes from Water

“…Polyoxometalates (POMs), as an outstanding class of anionic metal oxide clusters, have attracted great attention due to their earth-abundant source, rich topology and versatility, controllable shape and size, oxo-enriched surfaces, high electronegativity etc., 23 which have various applications in many fields, such as catalysis, 24 optics, 25 magnetism, 26 biological medicine, 27 and dye adsorption. 28 The strong attraction of POMs to cationic dyes suggests that they are potential and suitable adsorbents for selectively capturing cationic dyes.…”