A water-soluble mixed-valent {Mn 11 } cluster embedded heteropolyoxoniobate with magnetic properties.

A rare all-inorganic high-nuclearity mixed-valent {Mn 11 } cluster embedded polyoxoniobate, K 25 H 43 {(Te 4 Nb 9 O 33 ) 3 (Nb 6 O 19 ) 5 (Te VI Nb 5 O 14 )[(Te IV O 3 ) 2 (MnII7MnIII4O 19 )]}·97H 2 O (1), has been synthesized by a one-pot reaction. Compound 1 contains the largest manganese cluster {Mn 11 } core among polyoxoniobates reported to date. {Mn 11 } consists of three quasi-cubane {Mn 3 O 4 } units and is simultaneously encapsulated by lacunary α-Keggin {Te 4 Nb 9 O 36 } and Lindqvist {Nb 6 O 19 } units. Compound 1 exhibits significant magnetic anisotropy and excellent water solubility and stability. The findings suggest a new, all-inorganic polynulear Mn-based structural paradigm for aqueous solution chemistry and magnetic materials.