[(SeO) 4 P 8 W 48 O 184 ] 32– : a Tetraselenite‐Embedded Derivative of the Cyclic 48‐Tungsto‐8‐Phosphate

The tetraselenite‐incorporated 48‐tungsto‐8‐phosphate [(SeO) 4 P 8 W 48 O 184 ] 32– ( Se 4 P 8 W 48 ) has been synthesized by treating SeO 2 with the superlacunary, macrocyclic polyanion precursor [P 8 W 48 O 184 ] 40– ( P 8 W 48 ) in aqueous solution. Single crystal X‐ray diffraction analysis was carried out on K 26 Li 6 [(SeO) 4 P 8 W 48 O 184 ] · 98H 2 O [ KLi‐Se 4 P 8 W 48 , monoclinic space group C 2/ m, a = 35.3618(9) Å; b = 21.7869(6) Å; c = 24.6187(7) Å; β = 132.5822(15) °; V = 13965.4(7) Å 3 ; Z = 2]. The polyanion Se 4 P 8 W 48 contains four SeO 3 2– groups, adopting a trigonal‐pyramidal coordination geometry, grafted on the rim of the central cavity of P 8 W 48 . These four Se atoms are arranged in a coplanar fashion that is perpendicular to the main plane of P 8 W 48 , resulting in an overall D 2 h point group symmetry for Se 4 P 8 W 48 . The KLi‐Se 4 P 8 W 48 bulk material was characterized by X‐ray diffraction, infrared, UV/Uis, and NMR spectroscopy, as well as thermogravimetric and elemental analysis.