Na 7 Y 2 (P 2 O 7 ) 2 (P 3 O 10 ) – A New Layer and Tunnel Structure

A new layered phosphate, Na 7 Y 2 (P 2 O 7 ) 2 (P 3 O 10 ), containing both [P 2 O 7 ] 4− and [P 3 O 10 ] 5− groups, has been prepared. It crystallizes in the monoclinic space group P2/c with a = 16.205(4), b = 5.3746(9), c = 12.309(4) Å, β = 97.96(2)°, V = 1061.7(5) Å 3 and Z = 2. The structure was solved and refined to R 1 = 0.0298 and wR 2 = 0.0698 for 1844 independent reflections with I > 2σ(I). It consists of layers of corner and edge‐sharing YO 7 polyhedra, P 2 O 7 and P 3 O 10 groups. Each layer is built up from two parallel [YP 2 O 7 ] slabs, held together by the P 3 O 10 groups. This arrangement gives rise to intersecting tunnels within the layer. The Na + cations are located in the tunnels and between the layers. Both P 2 O 7 and P 3 O 10 groups contain unshared oxygen atoms directed toward the interlayer space and toward the tunnels. The P 2 O 7 groups show a staggered configuration. In addition to this original layered framework, the title compound provides the third example of a compound containing a mixed anion of [P 2 O 7 ] 4− and [P 3 O 10 ] 5− . The structure was compared with the two previously reported ones, containing such a mixed anion: NH 4 Cd 6 (P 2 O 7 ) 2 (P 3 O 10 ) [6] and Cs 2 Mo 5 O 2 (P 2 O 7 ) 3 · (P 3 O 10 ) [7].