Solvent-shielding allows the self-assembly of supramolecular 1D barium vanadate chains

Abstract

A proof of principle study is reported which introduces a new synthetic route for the assembly of 1-dimensional barium-linked polyoxovanadate chains. Bulky coordinating solvents featuring a binding site and a blocking site are employed and allow the controlled linkage of decavanadate clusters, [V₁₀O₂₈]⁶⁻, by barium(II) centres. Using the bulky solvent N-methyl-2-pyrrolidone (NMP), it is shown that a complex supramolecular architecture, {[Ba(nmp)₄(H₂O)]₂[H₄V₁₀O₂₈]}{[Ba(nmp)₃(H₂O)₂][H₃V₁₀O₂₈]}₂·2H₂O·10 NMP}_∞ (1) can be accessed where mono- and dinuclear barium units link decavanadate clusters into a linear chain. Using N,N-dimethyl formamide (DMF), a less complex architecture, [(Ba(dmf)₄]₂[H₂V₁₀O₂₈] (2), is formed where only dinuclear barium(II) linkages are observed. Theoretical Hirshfeld-analysis of the crystal lattices is used to examine the ‘shielding’ effect of the bulky ligands. ESI-mass-spectrometric studies give insight into potential fragments formed in solutions of 1 and 2.