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

Abstract

Connecting clusters: A new class of approximately 3.4 nm sized inorganic–organic–inorganic hybrids was synthesized by covalent functionalization of V3‐capped Wells–Dawson‐type clusters with linear bis(Tris) ligands (see scheme; TBA=nBu4N+). These hybrids were characterized using single‐crystal XRD and ESI‐MS techniques. Dynamic light scattering studies revealed the surfactant properties of these compounds, which lead to the formation of supramolecular vesicles in solutions.

A PGSE-NMR Study of Molecular Self-Diffusion in Lamellar Phases Doped with Polyoxometalates

“…[1][2][3][4][5][6] In this context, polyoxometalates, 7-9 thanks to their outstanding electronic properties, are inorganic building blocks that are becoming increasingly popular in soft-condensed matter studies. [10][11][12][13][14][15][16][17][18][19][20][21][22][23] Being negatively charged, they are most often associated to cationic surfactants, via ionic self-assembly processes. In a previous study, we formulated a hybrid system where the inorganic component is the [PW 12 O 40 ] 3-polyoxometalate (POM) anion ( fig.…”

Buildup of Amphiphilic Molecular Bola from Organic–Inorganic Hybrid Polyoxometalates and Their Vesicle‐Like Supramolecular Assembly

“…The effect of the solvent content can be further clarified when the x axis in Figure 3 is changed to 1/e r , with e r being the solvent dielectric constant. Although previous studies considered that the countercations (TBAs) play an important role on the vesicle formation, [9,19] our studies clearly show that the almost nonpolar solvent toluene is vital to the formation of vesicles for compounds 1-3. The result shows that the TBA cation in the absence of toluene does not promote any vesicle formation in the solution of 2, although the size of the assemblies increased with the increasing concentration of additional TBA cations in the mixed solution of acetonitrile/toluene (Figure S7 in the Supporting Information).…”

“…[9] The P 2 W 15 V 3 O 62 -tris-oxalamide dumbbell hybrid has a little less surface charge density than our three hexamolybdate hybrids (ca. 10 % difference), but the difference in their slopes shown in Figure 4 is significant.…”

“…The POM-organic hybrids containing both hydrophilic and hydrophobic domains can also self-assemble into various molecular architectures, which have been identified in different hybrid systems. [9,17] Two typical examples of vesicle formation are: Mn-Anderson POM with two long alkyl chains [17a] and two V 3 -capped WellsDawson-type clusters linked by organic ligands (dumbbells). [9] The current new bolaform hybrids can also be treated as "dumbbell"-shaped hybrids, but with flexible organic chains, and are ideal systems to explore the role of middle organic linkers in the self-assembly behavior of vesicle formation.…”

“…[2] This is due to their potential as building blocks to prepare various functional structures, such as micelles, vesicles, fibers, membranes, tubes, ribbons, and ropes for photoelectric devices, membrane-mimicking, nanoreactors, and drug delivery. [3,4] Although many functional groups have been used as the end unit of surface-active molecules, a bolaamphiphile with two organically derivatized polyoxometalates (POMs) as end groups, a class of unique metal oxide clusters grafted with organic ligands, [5][6][7][8][9] has never been reported. Among organically derivatized POMs, we are much more interested in organoimido-substituted POMs due to their potential applications in catalysis, photoelectric devices, and medicines.…”