Incorporation of Sulfate or Selenate Groups into Oxotellurates(IV): II. Compounds with Divalent Lead

Four mixed oxochalcogenate compounds in the systems Pb II / X VI /Te IV /O/(C), ( X VI = S and Se) were obtained as minority phases under hydrothermal conditions (210 °C, one week). Their compositions as determined on the basis of single‐crystal X‐ray diffraction data are Pb 3 (SeO 4 )(TeO 3 ) 2 , Pb 7 O 4 (SeO 4 ) 2 (TeO 3 ), Pb 5 (SeO 4 ) 2 (TeO 4 )(CO 3 ), and Pb 2 (SO 4 )(TeO 3 ). All crystal structures are centrosymmetric, and in each case the oxochalcogenate anions are isolated from each other. The Pb 2+ cations exhibit distorted coordination polyhedra with coordination numbers ranging from six to ten, in the majority of cases with a “one‐sided” coordination by oxygen atoms. The presence of the very rare square‐pyramidal Te IV O 4 4– anion distinguishes the structure of Pb 5 (SeO 4 ) 2 (TeO 4 )(CO 3 ) from the other structures, where the oxotellurate(IV) anions exist in the TeO 3 2– trigonal‐pyramidal configuration.