Synthese und Kristallstruklur von Triblei-Diphosphato-Borat-Phosphat, eine Verbindung mit einem ¹ _∞[(PO₄)₂BPO₄]^6–-Anion / Synthesis and Crystal Structure of Trilead-Diphosphato-Borate-Phosphate, a Compound with a ¹ _∞[(PO₄)₂BPO₄]^6–-Anion

Abstract

Single crystals of Pb 3 [(PO 4 ) 2 BPO 4 ] were obtained by melting B 2 O 3 , P 2 O 3 and PbO at 960 °C. The structure is related to the Ba 3 [(PO 4 ) 2 BPO 4 ] type. X-ray investigations on single crystals led to the space group Pbca - D 15 2h (Nr. 61) with a = 694.6(1), b = 1419.9(3), c = 2111.6(2) pm, Z = 8 . Boron and phosphorus are tetrahedrally coordinated by oxygen. The polyhedra form one-dimensional infinite helices that contain two additional PO 4 groups connected to the BO 4 -unit. Lead is eightfold coordinated by oxygen. The relation to the crystal structure of Ba 3 [(PO 4 ) 2 BPO 4 ] is discussed.