The crystal structures of two hydrogen monofluorophosphates: CsHPO3F and Cs-3(NH4)(2)(HPO3F)(3)(PO3F)

The crystal structures of two new hydrogen monofluorophosphates, CsWPO3F an d Cs-3(NH4)(2)(HPO3F)(3)(PO3F), have been determined at 180 K. The crystals of CsHPO3F are monoclinic, space group C2/m, with the unit cell dimensions of a = 14.478(5) A, b = 5.929(2) A, c = 5.413(2) A, beta = 103.30(3)degree s, V = 452.2(3) A(3), and Z = 4, R-1 = 0.0155 and wR(2) = 0.0378. Cs-3(NH4) (2)(HPO3F)(3)(PO3F) crystallizes in the monoclinic space group P2(1)/c, wit h a = 20.619(4) A, b = 12.076(2) A, c = 15.856(3) A, beta = 102.58(2)degree s, V = 3853(1) A(3), and Z = 8, R-1 = 0.0155 and wR(2) = 0.0976. In the str ucture of CsHPO3F, two symmetrically disordered hydrogen bonds (2.527(2) A) connect two HPO3F units to form closed dimers. Cs-3(NH4)(2)(HPO3F)(3)(PO3F ) contains a complex hydrogen bond network(N-H ... O and O-H ... O) with tw o different types of P tetrahedra, PO3F and HPO3F. The structure contains a complex network of hydrogen bonds. Units of 2NH(4) and PO3F (I) and Cs and HPO3F (II) are found in and around planes parallel to (x0z). Fluorine is n ot involved in the hydrogen bonding in either of the structures.