Diversified polyoxovanadate derivatives obtained by copper(i)-catalysed azide–alkyne cycloaddition reaction: their synthesis and structural characterization

Abstract

In this work, we confirmed that the copper-catalysed azide–alkyne cycloaddition (CuAAC) reaction is an effective method for the organic-functionalization of polyoxometalates (POMs). Herein, for the first time, four novel 1,2,3-triazole functionalized polyoxovanadate (POV) organic–inorganic hybrids, (Bu₄N)₂[V₆O₁₃{(OCH₂)₃C₅H₆N₃O}₂]·1.5CH₃CN 2, (Bu₄N)₂[V₆O₁₃{(OCH₂)₃C₇H₈N₃O₂}₂]·2CH₃CN 3, (Bu₄N)₂[V₆O₁₃{(OCH₂)₃C₁₁H₁₀N₃}₂] 4 and (Bu₄N)₂[V₆O₁₃{(OCH₂)₃C₁₀H₇N₃Cl}₂] 5 were prepared through the CuAAC reaction using the azide functionalized hexavanadate, (Bu₄N)₂[V₆O₁₃{(OCH₂)₃CCH₂N₃}₂]·2.5CH₃CN 1, as the precursor, where CuI was used as the catalyst and N,N-diisopropylethylamine (DIPEA) as a stabilizer for Cu^I. All the four compounds were structurally and compositionally characterized by single-crystal X-ray diffraction, elemental analyses, powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), ¹H NMR, ESI-MS, UV-Vis and thermogravimetric analysis (TGA).