A Novel Vanadosilicate with Hexadeca‐Coordinated Cs+ Ions as a Highly Effective Cs+ Remover.

The mixed-valent vanadosilicate K4.6{(VIVO)0.8 (VVO)1.2H2O}2 {Si12O32 [Cs(H2O)4]}·xH2O is obtained by partial oxidation of Na7{(VIVO)2H2O}2 {Si12O32 [Cs(H2O)4]}·xH2O with Br2 in an organic solvent (not specified) followed by cation exchange using a KCl solution (80 °C, 6 h).