Synthesis and Crystal Structure of Pb 3 O 2 (SeO 3 )

Single crystals of Pb 3 O 2 (SeO 3 ) have been prepared hydrothermally at 230 °C. The structure (orthorhombic, Cmc 2 1 , a = 10.529(2), b = 10.722(2), c = 5.7527(12)Å, V = 649.5(2)Å 3 ) has been solved by direct methods and refined to R 1 = 0.059 on the basis of 615 unique observed reflections (| F o | = 4σ F ). The structure is based upon double [O 2 Pb 3 ] 2+ chains of edge‐sharing [OPb 4 ] 6+ tetrahedra. These [O 2 Pb 3 ] 2+ chains run parallel to [001], and their planes are parallel to (010). The pyramidal (SeO 3 ) 2— anions are located between the chains; their triangular oxygen atom bases lie parallel to (001) and all (SeO 3 ) 2— groups are pointing in the same direction. A short compilation of [O 2 M 3 ] chains of oxocentred M 4 tetrahedra in minerals and inorganic compounds is provided.