The oxochlorotantalates (PPh4)2[Ta2OCl9]2 • 2 CH2Cl2, (PPh4)2[Ta2OCl10] • 2 CH3CN, and (K-18-crown-6)4[Ta4O6Cl12] • 12 CH2Cl2

(K-18-crown-6)(4)[Ta4O6Cl12]. 12CH(2)Cl(2) was obtained from a reaction of tantalum pentachloride, K2S5 and 18-crown-6 in dichlormethane. According to its crystal structure analysis it is tetragonal (space group I (4) over bar 2d) and contains [Ta4O6Cl12](4-) ions that have an adamantane-like Ta4O6 skeleton. Each K+ ion is coordinated by the oxygen atoms of the crown ether molecule from one side and with three Cl atoms of one [Ta4O6Cl12](4-) ion from the opposite side. (PPh4)(2)[Ta2OCl10]. 2CH(3)CN was a product from PPh4Cl and TaCl5 in acetonitrile in the presence of Na2S4. Its crystals are monoclinic (space group P2(1)/c) and contain centrosymmetric [Ta2OCl10](2-) ions having a linear Ta-O-Ta grouping with short bonds (Ta-O 189 pm). TaCl5 and H2S formed a solid substance (TaSCl3) from which a small amount of (PPh4)(2)[Ta2OCl9](2). 2CH(2)Cl(2) was obtained by the reaction with PPh4Cl in CH2Cl2. The anions in the monoclinic crystals (space group P2(1)/n) consist of two Ta2OCl9- units which are joined by chloro bridges; each Ta2OCl9- unit has a nearly linear Ta-O-Ta group with differing bond lengths (179 and 202 pm). The oxygen in the compounds probably was introduced by traces of water in the crown ether, acetonitrile or H2S, respectively.