[C4N2H12]2[In3(HPO4)5(H2PO4)F2]: The first 2-D fluorinated indium phosphate with double-sheet layers and 8-ring channels

A new structure type of layered fluorinated indium phosphate with In/P ratio of 1/2 [C4N2H12]2[In3(HPO4)5(H2PO4)F2] (1), has been hydrothermally synthesized. It is the first 2-D fluorinated indium phosphate comprising of double-sheet layers with 8-ring channels and diprotonated piperazine cations.