One novel 3-D vanadoborate with unusual 3-D Na–O–Na network

Abstract

A new 3-D vanadoborate {Na₂B₁₈V₁₂O₅₄(OH)₆(H₂O)[Na₈(H₂O)₁₆]}·2H₂O (1) has been hydrothermally synthesized and structurally characterized. The crystal of 1 is built up from an unusual 3-D Na–O–Na network and entrapped [V₁₂B₁₈O₅₄(OH)₆(H₂O)]¹⁰⁻ clusters (denoted [V₁₂B₁₈]). Such a Na–O–Na network is constructed by the linkage of rare 1-D helical [Na₄(H₂O)₈⁴⁺]_n chains and [NaO₆] octahedra. 1 represents the rare example of extended POMs with 3-D inorganic metal–oxygen networks. Magnetic measurements illustrate that 1 has antiferromagnetic exchange interactions between metal centers.