Synthesis and crystal structure of a new gallium phosphate with 14-ring channels

The synthesis and crystal structure of a new 14-membered ring gallium oxyfluorophosphate are described: DIPYR-GaPO: Ga7P6O28F3C10N2H16, M-r=1343.1, space group P (1) over bar, a=12.000(3) Angstrom, b=13.895(4) Angstrom, c=10.280(4) Angstrom, alpha=101.09(3)degrees, beta= 100.91(2)degrees, gamma=106.41(2)degrees, D-c=2.83 g cm(-3), F(000)=1297, R=2.89%, R-w=3.63%. The product was obtained by hydrothermal synthesis at 170 degrees C in a reaction using two amines as structure-directing agents in the HF-Ga2O3-P2O5 system: pyridine and benzylviologen dichloride. The benzylviologen dichloride decomposed during the reaction to form 4,4'-dipyridyl, which was found in the 14-ring channels together with pyridine. Intraframework hydrogen bonding appears to play an important role in determining the shape of the pores.