Direct Synthesis of Controlled‐Size Nanospheres inside Nanocavities of Self‐Organized Photopolymerizing Soft Oxometalates [PW₁₂O₄₀]_n (n=1100–7500)

Abstract

The unusual self-assembly of {(BMIm)2 (DMIm)[PW12 O40 ]}n (n=1100-7500) (BMIm=1-butyl-3-methylimidazolium, DMIm=3,3'-dimethyl-1,1'-diimidazolium) soft oxometalates (SOMs) with controlled size and a hollow nanocavity was exploited for the photochemical synthesis of polymeric nanospheres within the nanocavity of the SOM. The SOM vesicle has been characterized by using several techniques, including dynamic light scattering (DLS), static light scattering (SLS), attenuated total reflection (ATR) IR spectroscopy, Raman spectroscopy, microscopy, and zeta-potential analysis. The self-assembly and stabilization of this soft-oxometalate vesicle has been shown by means of counter-ion condensation. The immediate implication of such stabilization-the variation of the dielectric constant with the hydrodynamic radius of the vesicle-has been used to synthesize vesicles of controlled size. Such vesicles of varying size have been used as templates for polymerization reactions that produce polymeric spheres of controlled size. Direct evidence shows that the SOM behaves as a model heterogeneous catalytic system. Such surfactant- and initiator-free photochemical synthetic routes for obtaining uniform latex spheres could be used in the making of optical bandgap materials, inverse opals, and paints.

Photochemical reduction of carbon dioxide coupled with water oxidation using various soft-oxometalate (SOM) based catalytic systems

“…SOMs can undergo topological transformation, 51 can be used in patterning 52,53 and as active particles. 46 The catalytic activity of SOMs has also been explored in various types of reactions viz., in photo-polymerization [54][55][56] and photochemical water oxidation. 57 In this article we have shown that SOM type materials based on oxo-molybdate and oxo-tungstate clusters can efficiently catalyse the reduction of CO 2 to HCOOH/HCHO by transferring the electrons and protons generated from oxidation of water.…”

A newly designed softoxometalate [BMIm]2[DMIm][α-PW12O40]@hydrocalumite that controls the chain length of polyacrylic acid in the presence of light

“…1 forms vesicle like superstructure in DMSO-water mixture. 53 The hydrodynamic radius of this vesicle can be controlled by changing the polarity of system. 53 We now synthesize a new composite material based on hydrocalumite and 1, and to do so we have added 1 (DMSO solution) in a dilute dispersion of hydrocalumite.…”

“…Our group already reported that SOM can be synthesized from 1 which forms vesicle like superstructure in water dispersion. 53 Using this superstructure as photocatalyst we could synthesize polymeric spheres. But now we want to control the chain length of polyacrylic acid, using a two component SOM and an electroactive template which will facilitate the catalytic process.…”

Light Driven Water Oxidation Coupled With C‐N Coupling Reaction Using a Hybrid Cu‐PW12O40 Based Soft‐Oxometalate

“…The immobilization of the POM moiety on the electro active surface can enhance the catalytic activity of these materials ,. POMs can also exist in a colloidal state of soft‐oxometalates (SOMs) . We have recently shown that soft oxometalates based on several different oxometalates can act as active catalyst for photo chemical oxidation of water without the need of a photosensitizer and a sacrificial electron donor ,…”