Ionic self-assembly of organic-polyxometalate hybrids in solid state and its charge transfer properties

Highlights: • Dye-polyoxometalate hybrids were prepared by ionic self-assembly. • Hybrids form colored vesicles in ethanol/water under fluorescence microscope. • There are charge-transfer properties in three hybrids. • Three hybrids show layered structure in aggregates. -- Abstract: The organic cations based on perylene diimide skeleton was employed to encapsulate H₃[PW₁₂O₄₀], K₅[Eu(SiW₁₁O₃₉)], Na₉[EuW₁₀O₆] to construct organic-polyoxometalates hybrids by electrostatic interaction. We studied the ionic self-assembly of hybrids in ethanol/water mixed solution under fluorescence microscope and scanning electron microscopy. Layered-packing modes in solid state were explored by high-resolution transmission electron microscopy. Charge transfer properties of hybrids between organic donors and POMs acceptors within the molecules were studied by solid diffuse reflectance spectroscopy. Hybrids can form colorful multi-lamellar vesicles with different morphologies and show the typical charge transfer characteristics. The comprehension for the self-assembly morphology and solid structure of organic-polyoxometalate hybrids would help us to use easily modified organic moiety and functional inorganic polyoxoanions as blocks to build novel and giant supramolecular architecture.