Self-assembly of high-nuclear core–shell polyoxovanadates with Lindqvsit templates

Abstract

Only rarely have polyoxometalates been recorded to form core–shell clusters, which presumably relates to the scarcity of appropriate building blocks. Herein, two high-nuclear core–shell polyoxophosphovanadates [M₆O₁₉]²⁻⊂[Na₈V^V₆V^IV₁₂O₁₈(PhPO₃)₂₄]²⁺ (M = W 1, Mo 2) are synthesized utilizing Lindqvist polyoxometalates as templates. Both clusters exhibit a nested three-shell architecture characterized by an octahedron@cube@octahedron configuration. The outer shell [V^V₆V^IV₁₂O₁₈(PhPO₃)₂₄]⁶⁻ consists of two simple {VO₅} and {PhPO₃} building blocks connected alternately and exhibits the same octahedral geometry as the inner core [M₆O₁₉]²⁻ due to anionic template effects. To the best of our knowledge, compounds 1 and 2 represent the first core–shell polyoxovanadates templated by Lindqvist polyoxometalates. Furthermore, compound 1 demonstrates efficacy and stability as a catalyst for the oxidation of sulfide. This work provides a new perspective on the construction of novel core–shell polyoxometalates.