The Synthesis and Crystal Structures of Two New Hydrated Sodium Monofluorophosphates: NaHPO_3F.2.5 H_2O(I) and Na_2PO_3F.10 H_2O(II)

摘要

The structures of two new sodium salts of monofluorophos- phoric acid, Na8P03F .2.5820 (1) and Na2P03F ..10820 (II), were determined with single-crystal X-ray diffraction at 160 K. I is monoclinic with the space group C2/c, a = .19..1.12(4), b = 5.34.1 (.1), c = .12.727(3) A, p = .1.10..18(3)0, V= .12.19.4(4) A3, and Z= 8 (R. = 0.0276 and wRz = 0.0647). II crystallizes in the monoclinic space group, P21/c, a= .1.1.380(3), b = .10.234(2), c=.13.051(4)A, p=106.49(3)O, V=1457.4(7)A3, and Z=4 (R. = 0.0266 and wRz = 0.0581). The crystal structure of I con- tains hydrogen-bonded zigzag chains of 8P03F tetrahedra. The fluorine atom does not participate in the hydrogen bonding system. In the structure of II, hydrogen bonds create a complex structure of water molecules connected to each other and to the PO3F tetrahedron. The structure is isotypic to NaZS04. .10820 with two disordered hydrogen atoms instead of four. The fluorine atom acts as an acceptor in two of the hydrogen bonds.