Self-Assembly of Organic−Inorganic Hybrid Amphiphilic Surfactants with Large Polyoxometalates as Polar Head Groups

Abstract

Mn-Anderson-C6 and Mn-Anderson-C16, A type of inorganic-organic hybrid molecules containing a large anionic polyoxometalate (POM) cluster and two C6 and C16 alkyl chains, respectively, demonstrate amphiphilic surfactant behavior in the mixed solvents of acetonitrile and water. The amphiphilic hybrid molecules can slowly assemble into membrane-like vesicles by using the POM clusters as polar head groups, as studied by laser light scattering and TEM techniques. The hollow vesicles have a typical bilayer structure with the hydrophilic Mn-Anderson cluster facing outside and long hydrophobic alkyl chains staying inside to form the solvent-phobic layer. Due to the rigidity of the POM polar heads, the two alkyl tails have to bend significantly for the vesicle formation, which makes the vesicle formation more difficult compared to some conventional surfactants. This is the first example of using hydrophilic POM macroions as polar head groups for a surfactant system.

Redox-active organic–inorganic hybrid polyoxometalate micelles

“…12 In this covalent approach, the inorganic POMs are functionalised with organic groups, such as long aliphatic alkyl chains, to form organicinorganic hybrid molecules which can assemble to form micellar, vesicular and liquid crystal-like states. Polarz, Song, Cronin, Liu and their co-workers have pioneered the field of covalently functionalized polyoxometalate-surfactants, and shed light on their complex architectures and self-assembly, [13][14][15][16][17][18][19][20][21][22][23][24] _ENREF_15 however, relatively little is known about the physicochemical properties of the nanoscale hybrid assemblies, and in particular the translation of POM functionality across the scales, from molecular to supramolecular and bulk.…”

Synthesis of Modular “Inorganic–Organic–Inorganic” Polyoxometalates and Their Assembly into Vesicles

“…[12][13][14] In this respect, we have been targeting the synthesis of modular functional POM-based organic-inorganic amphiphiles for vesicle assembly. [15] Herein we report the synthesis and structural characterization of two members of a new class of "inorganic-organicinorganic" hybrid molecules derived by grafting linear bis-(Tris) ligands onto the V 3 , respectively, at reflux in dry acetonitrile. The compounds thus obtained were characterized by elemental analyses, IR and NMR spectroscopy, ESI-MS, and (in the case of 1) also by single-crystal X-ray crystallography (Figure 1).…”

Magnetic surfactants

“…So far the review has covered ionic surfactants with metal counterions, however surfactants that contain [85]. Since then work in this area has intensified due to potential applications ranging from catalysis and energy storage to medicine and magnetic materials [86].…”