Compositional introduction of lithium ions into conductive polyoxovanadate–surfactant hybrid crystals

Abstract

Polyoxovanadate–surfactant hybrid layered crystals were successfully synthesized as single crystals by employing a primary alkylammonium cation, octylammonium ([C₈H₁₇NH₃]⁺, C₈NH₃). Two types of hybrid crystals with the formulae [C₈H₁₇NH₃]₆[V₁₀O₂₈]·2H₂O (C₈NH₃–V₁₀) and [C₈H₁₇NH₃]₄Li₂[V₁₀O₂₈]·4C₂H₅OH·6H₂O (C₈NH₃–Li–V₁₀) were obtained by different synthetic procedures. Changing the synthetic conditions enabled the precise introduction of lithium cations into the polyoxovanadate–surfactant hybrid crystals according to compositional control. C₈NH₃–V₁₀ contained a discrete [V₁₀O₂₈]⁶⁻ anion, while C₈NH₃–Li–V₁₀ was composed of a [V₁₀O₂₈]⁶⁻ anion associated with two lithium cations formulated as {[Li(H₂O)₃]₂[V₁₀O₂₈]}⁴⁻. The conductivities of C₈NH₃–V₁₀ and C₈NH₃–Li–V₁₀ were investigated under anhydrous conditions at intermediate temperatures.