“CLICKable” azide-functionalized phosphonates for the surface-modification of molecular and solid-state metal oxides

Abstract

The covalent functionalization of metal oxide surfaces with organic ligands gives unique organic-inorganic hybrids. Here we report a bifunctional organic tether combining a phosphonate for metal oxide anchoring with an organic azide for attachment of organic groups. Stable binding of the tether to molecular and solid-state metal oxides is demonstrated and the subsequent "CLICKability" of the TiO-anchored tether is shown. The phosphonate-azide reported could in future allow the general linkage of functional organic groups to metal oxides.

Multifunctional Polyoxometalate Platforms for Supramolecular Light‐Driven Hydrogen Evolution**

“…Thus, light-driven catalytic studies were performed in waterfree, de-aerated DMF solutions containing the respective catalyst POM-PtX (12.5 μM), the photosensitizer PS (125 μM) and triethyl amine/acetic acid (TEA (1.0 M)/HAc (0.2 M)) as sacrificial proton/electron donors; this experimental setup has been adapted from earlier POM-based HER studies. [48,[50][51][52] The samples were irradiated under an Ar atmosphere using monochromatic LEDs (λ max = 470 nm, P ~40 mW cm À 2 ) at 25 °C. Hydrogen evolution was quantified by calibrated gas chromatography.…”

Multifunctional Polyoxometalate-Platforms for Supramolecular Light-driven Hydrogen Evolution

“…Thus, light-driven catalytic studies were performed in water-free, de-aerated DMF solutions containing the respective catalyst POM-PtX (12.5 µM), the photosensitizer PS (125 M) and triethyl amine/acetic acid (TEA (1.0 M) / HAc (0.2 M)) as sacrificial proton/electron donors; this experimental setup has been adapted from earlier POM-based HER studies. 44,[46][47][48] The samples were irradiated under an Ar atmosphere using monochromatic LEDs (λmax = 470 nm, P ~ 40 mW cm -2 ) at 25°C. Hydrogen evolution was quantified by calibrated gas chromatography.…”

Supramolecular Aggregation Control in Polyoxometalates Covalently Functionalized with Oligoaromatic Groups

“…One promising approach to overcome this bottleneck is the introduction of organic azide functions covalently attached to the POM, [23–25] so that subsequent CLICK chemistry [26] (i. e., copper catalyzed alkyne‐azide cycloaddition) enables versatile post‐functionalization. To access “CLICKable” POMs, different cluster architectures have been covalently functionalized with organic azides, including the Anderson anion [23,27] as well as the Dawson anion [28,29] .…”