CRYSTAL STRUCTURES OF TETRAMETHYLAMMONIUM SALTS [XW18O60]9–

Crystal structures of tetramethylammonium salts of [XW18O60]9– anions (X = As3+, Sb3+) are described for the first time. The structures of ((CH3)4N)6H3[AsW18O60]·3.8H2O (1) and ((CH3)4N)6H2.5Na0.5[SbW18O60]· 7.7H2O (2) are determined by single crystal X-ray diffraction. In the structure of complex 2, the [β-SbW18O60]9– isomer is discovered for the first time.