Synthesis and Structural Characterization of Lanthanide‐Containing Polytungsto‐antimonate [{Sb 3 (µ 3 ‐O) 2 Ln(H 2 O)Ln(H 2 O) 2 } 2 (SbW 10 O 37 ) 2 (SbW 8 O 31 ) 2 ] 22 – Molecules Deriving from the Decomposition of the [Sb 8 W 36 O 132 ] 24 – Macroanion

Reaction of the tungsto-antimonate [Sb 8 W 36 O 132 ] 24-polyoxometalate with late trivalent lanthanide cations (from Gd to Lu) gives rise to the formation of eight isostructural molecular compounds [{Sb 3 ( 3-O) 2 Ln(H 2 O)Ln(H 2 O) 2 (SbW 10 O 37)(SbW 8 O 31)} 2 ] 22-(Ln = Gd III (1), Tb III (2), Dy III (3), Ho III (4), Er III (5), Tm III (6), Yb III (7), Lu III (8)). All compounds were characterized by routine solid-state techniques (IR spectroscopy, TGA, single crystal X-ray diffraction) and, by SAXS measurements in aqueous solutions to assess their stabilities. Luminescent properties of compounds 5 and 7 were also studied.