A new lead Mo(IV) phosphate with a tunnel structure: Pb2Mo2O(PO4)2P2O7

A molybdenum (IV) phosphate containing lead, Pb 2 Mo 2 (PO 4 )2P 2 O 7 , has been synthesized for the first time. It crystallizes in the space group C 2/ c with a =14.098(1) A, b =14.187(2) A, c =6.5592(4) A and β =102.08(1)°. Its original tunnel structure, built up of Mo 2 O 11 bioctahedra, P 2 O 7 and PO 4 phosphate groups can be described from the assemblage of [Mo 4 P 4 O 24 ] ∞ ribbons interconnected through monophosphate groups. The stereoactivity of the 6 s 2 lone pair of Pb 2+ , which is surrounded by nine oxygen atoms, is discussed.