Structure of dichromate-type lead pyrophosphate, Pb2P2O7

Lead pyrophosphate, Pb2P2O7, crystallizes in the triclinic space group P1 (Z = 4) with a = 6.914(2), b = 6.966(2), c = 12.751(4) A; α = 96.82(3), β = 91.14(3), γ = 89.64(3)°; and V = 612.0(6) A3. Structural refinement data were collected using an automated diffractometer with MoKα radiation. The lead pyrophosphate structure was refined by a full matrix to an R of 0.069 (Rw = 0.067) using 2637 unique reflections. The structure has two unique diphosphate groups that are repeated by lattice translations to form sheets of diphosphate groups. The P2O7 groups, dichromate type, are eclipsed to within 9.4 and 13.5°. The Pb2+ ions are eight- and nine-coordinated to oxygen atoms with average experimental interatomic distances of 2.695 and 2.767 A, respectively.